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Ten Tips for Better Prints
by Eric Chan | March 1, 2008

My first article for NatureScapes.Net was a whirlwind tour of the world of inkjet printing. It provided an overview of the essentials, such as equipment choices (printer, ink, and paper) and color management. Read my previous article »

The aim of this article is a little different. It assumes you are familiar with inkjet printing already and want to take your skills to the next level. I hereby present MadManChan’s Ten Tips for Better Prints: a collection of tips, tricks, and techniques that I’ve found useful when preparing my own images for print. I have tried to choose tips that do not require you to spend additional money – e.g., buying custom profiles, your own profiling packages, or additional software plug-ins – but I do assume that you have a recent version of Photoshop, such as CS, CS2, or CS3. I have also tried to choose tips that seem to be less well-known (or at least, I don’t see them discussed as frequently).

Table of Contents:

Tip 1: Pick the Paper That Suits the Image

Tip 2: Use Big Black and White Borders During Editing

Tip 3: When Black Isn’t Really Black

Tip 4: Print Sharpening

Tip 5: Don’t Sharpen Smooth Areas

Tip 6: Noise Can Be a Good Thing

Tip 7: Checking Gamut Boundaries and Handling Out-of-Gamut Colors

Tip 8: Use Standard Test Images to Troubleshoot

Tip 9: Shake It Up!

Tip 10: Presentation Counts

Wrap-up

Stata in Snow, Cambridge, MA

Before we begin, let me clarify some terminology and abbreviations that I’ll use throughout this article. Many modern inkjet printers have two kinds of black ink: Photo Black (PK) and Matte Black (MK). Glossy, luster, semi-gloss, and the new F-type papers are often called photo papers and are designed to be used with the Photo Black ink, so I’ll use the abbreviation “PK papers” to refer to them. Similarly, I’ll use the abbreviation “MK papers” to refer to matte papers designed to be used with the Matte Black ink, such as alpha cellulose and cotton rag papers.

I use the term “printing system” to refer to a specific combination of printer, ink, paper, and driver settings. It is important to recognize that all components affect the final print. In particular, printer profiles are designed to capture the behavior of an entire printing system, not just a part of it.

With that out of the way, let the tips begin!

Tip 1: Pick the Paper That Suits the Image

Matte or glossy? Textured or smooth? Cool or warm? Pick the paper that suits the image.

The choice of paper plays an important role in determining the “look” of the print. Modern inkjet printers work beautifully with both PK and MK papers. Consider whether a given image calls for a smooth surface or a textured one, a glossy reflective surface or a diffuse matte surface, a cool white base or a warm yellow base. Many papers, such as Epson Premium Luster (now Ultra Premium Photo Paper Luster), will certainly “work well” across a wide range of images but may not be optimal choices for a given image. At the beginning, pick one or two papers and really learn to work with them. As you gain experience, learn to recognize the strengths and weaknesses of the papers you work with and consider trying new ones to improve your prints.

Example 1: Low-contrast “foggy” images often work well with matte papers. High-gloss reflective papers may interfere with the “quiet mood” of such images.

Example 2: Images with snow often benefit from lightly-textured matte papers. The texture gives the impression of “depth” and “3D-ness” which enhances snowy images. In general, images whose content contains texture (e.g., rocks, tree bark) often work well with textured papers. But textured surfaces may detract from images which have lots of smooth tonal areas, such as skies, fog, and skin in human portraits.

Example 3: When printing a single project, such as a portfolio of 10 images, it’s fine to compromise by choosing a single paper for all images in that portfolio. This provides consistency in form and presentation. Also see Tip 10 below.

Images in a portfolio all printed on the same paper

Example 4: Shadow detail is inherently harder to bring out on MK papers than on PK papers. For images with significant shadow detail, you may find PK papers to be more suitable.

Example 5: Prints that are designed to be held in the hand often work better on thicker papers (e.g., thick cotton rag papers or other heavy fiber-based papers). Thicker papers also leave a more favorable impression. See Tip 10 below.

Example 6: Learn to recognize specific (and unusual) weaknesses of papers. For instance, greens look muddy when printing color images from an Epson 3800 printer on Hahnemühle Photo Rag 308. There is a specific interaction within this printing system that causes greens to run together and appear tonally indistinct (and is not solved via a profile). One solution is to choose another paper when printing images with significant greens using an Epson 3800.

In short, choose your paper carefully. It makes a difference!

Tip 2: Use Big Black and White Borders During Editing

My next two tips address tonal range and tone reproduction.

Our eyes and brains judge brightness on a relative scale, not an absolute scale. What’s amazing is how our judgment can be affected by the background: the overall tone as well as the arrangement of tones and shapes in the background. For example, in the illustration below, two small gray squares are placed against a dark background (left) and a light background (right). The right square appears somewhat darker than the left one, but they’re actually the same shade of gray.

Here’s an even more convincing illustration, known as White’s Illusion. There are six gray bars set against a background of alternating black and white horizontal stripes. The three bars on the right side appear significantly darker than the three bars on the left, but all six bars are exactly the same. (Bring the image into Photoshop and use the Color Picker to convince yourself!)

Interesting stuff, but what does this have to do with images? Well, backgrounds matter when viewing images. Consider: printed images are often surrounded by white, such as the white border of the paper, a large white mat border (for matted prints), or the white of the background wall. In contrast, images edited in applications such as Photoshop or Lightroom are often viewed against a medium or dark gray background. When these images are then viewed against a white background, they may seem too dark by comparison. This is one reason why a printed image sometimes appears darker when compared to the image on the display.

If you don’t believe this, consider the following example. The image below appears to have several dark areas of solid black without much shadow detail.

The shadows appear quite dark with little detail.

But when the exact same image is viewed against a black background (see below), it becomes apparent that there is plenty of shadow detail, and the dark areas don’t seem so dark anymore. Context is everything.

The shadows look brighter with more detail.

How can we exploit this behavior of the human visual system to make better prints? During the editing process, we can surround our images by big white or big black borders to help our brains adjust to the background. We can better judge the overall tone, making adjustments as needed.

Let’s start by discussing black backgrounds. Black backgrounds are useful for judging shadow detail and optimizing black density (also see Tip 3 below). With a black background, you may notice that areas that you previously thought were pure black are in fact not-so-black. Thus you may need to fine-tune your image’s black point (e.g., with Levels). If you prefer a more analytical approach, you can also use the Color Picker (eye dropper) in Photoshop to check the actual values of the pixels. As a side note, I also find a black background useful for performing cropping refinements, since it becomes much easier to see if there are any distracting elements at the edges of the image.

The easiest way to get a black background in Photoshop is to press the F key twice to go into full-screen mode. If you use Lightroom, you can right-click on the area outside the image and change the background color to five different shades of gray, including white and black. Another approach in Lightroom is to press the L key twice to enter “lights out” mode; use Lightroom’s Preferences to set the “lights out” background color.

Now let’s talk about white backgrounds. I suggest using a white background to judge overall tone and highlight detail. This is particularly important when preparing an image for print. In Photoshop, one way to get a big white border around the image is to go to the Image menu, choose Canvas Size, and add a generous amount of blank white canvas around the image. Suddenly, an image that looked just right may look too dark. Similarly, highlights that previously looked bright and white may now look dim and dull. Thus you may need to fine-tune the white point of your image (e.g., with Levels) and adjust the overall tonality of the image (e.g., bump up the midtones with Levels or Curves).

When using these techniques, make sure you are viewing your image at an appropriate zoom level: leave plenty of empty space around all four edges of the image. Otherwise there won’t be enough black or white surrounding the image for your eyes to adjust to the background.

Tip 3: When Black Isn’t Really Black

The dynamic range of a print is determined by how much light reflects off of the surface at the tonal extremes. This is easiest to understand by considering the following two experiments.

Let’s say we create a blank white canvas in Photoshop (RGB = (255, 255, 255)) and print it out on paper. In most cases, the printer won’t actually apply any ink to the sheet. If we hold the print under a viewing light, all we see is a blank white sheet. Since there is no ink to absorb any of the light shining on the paper, this is the brightest that any print on this paper can look: maximum reflectance.

Now let’s do the same thing again, except this time we use a pure black canvas (RGB = (0, 0, 0)) and print it out. In this case, the printer will spit out a lot of ink onto the printed sheet. This ink absorbs a lot of light and reflects only a little bit; hence it appears to be a big black patch. This is the deepest black that the printer can produce on this paper: minimum reflectance.

Putting these two ideas together, we see that the dynamic range of an inkjet print is defined at the extremes by paper white (no ink, as described in the first case) and paper black (maximum ink, as described in the second case). Paper white and paper black numerically correspond to 8-bit RGB = (255, 255, 255) and RGB = (0, 0, 0), respectively.

That seems reasonable enough. But now let’s understand what this means in practice. If you’re trying to maximize the dynamic range in your prints, you need to use the entire tonal range available. That means the highlights in your image need to be (255,255,255) and the deepest shadows need to be (0,0,0). Pinning the deepest shadows to (0,0,0) usually has a much greater effect in the print compared to pinning the highlights to (255,255,255), so the rest of this section will focus on optimizing the shadows However, the same principles also apply to the highlights.

As an exercise, give the following a try: select the Color Picker tool in Photoshop, move it over one of the dark regions of your image, and check the RGB values in the Info palette. If the readout values aren’t (0,0,0), then those pixels won’t print out as deep a black as your printer is capable of delivering – and hence the dynamic range of the print won’t be fully realized.

For example, let’s take a look at this image of Landscape Arch below. The bottom quarter of the image is pure black. Or is it? If you bring the image into Photoshop and use the Color Picker, you’ll find that the RGB values of the pixels in that bottom region are (2,2,2), not (0,0,0). I normally print this image on matte paper, and matte papers are limited in their dynamic range (because blacks aren’t that deep on matte papers to begin with). The difference between (2,2,2) and (0,0,0) is indeed visible in the print.

Landscape Arch, Arches National Park, Utah - It's an arch, yes, but is it black?

Maximizing the dynamic range of the print is easy to accomplish by fine-tuning the white and black points of your image in Photoshop. One method is to use the Levels tool (adjust the leftmost and rightmost input sliders) or Curves tool (adjust the bottom-left-most and top-right-most points) to edit the black and white points of your image. As usual, I would recommend editing using an adjustment layer, so that the edit can later be refined or undone. Another advantage of working with an adjustment layer is that you can combine your edit with a layer mask, thereby restricting your tone tweaks to the regions of the image that require it (i.e., the extreme shadows and highlights).

It is often helpful to take an analytical approach instead of a visual approach. This is sometimes called “editing by the numbers” since you end up relying on numeric values rather than what you see on the screen. It’s a good idea to use the Color Picker tool and the RGB readouts in the Info palette to check that you’re actually reaching (0,0,0) and (255,255,255) in the desired areas. As indicated earlier, there’s typically a more dramatic effect when optimizing the black point, so pay special attention to the shadows.

A visual method for checking that the desired shadow areas of your image reach RGB (0,0,0) is to press the Alt/Option key while clicking on the left input slider on the Levels tool. This produces a visualization of the image areas that are clipped by the black point. Pixels that have reached (0,0,0) are shown in solid black. If the areas that you wish to appear black don’t show up in the visualization as black pixels, simply drag the left input slider to the right (while continuing to press the Alt/Option key) until the black pixels appear.

As another example, consider the image below. The area highlighted in red appears pretty dark, but how black is it? Open it in Photoshop and use the Color Picker to find out!

Scraggly Branches, Monument Valley

Summary: As we saw in the previous tip, the eye easily can be fooled by context (e.g., the background). Image regions that appear black on-screen may not actually print out that way. Use the Color Picker to double-check. If the pixel value isn’t (0,0,0) then it isn’t black!

Tip 4: Print Sharpening

My next three tips are focused on optimizing details and image texture.

In order for printed images to appear sharp, the images have to be sharpened specifically for the printing process. Why? One reason is that ink drops bleed as they get absorbed into the paper coating, causing softening of image detail. We can compensate for this softening by applying print sharpening (also called output sharpening) before printing the image. Since ink bleeding generally occurs more on MK papers than on PK papers, stronger output sharpening is needed with MK papers.

Autumn Color, Northern Vermont - I'll use this image as an example for print sharpening.

Note that print sharpening shouldn’t be confused with sharpening that is performed during editing for other reasons, such as for effect (creative sharpening) or to compensate for the loss of sharpness during the image capture stage (capture sharpening). Print sharpening is only designed to compensate for problems that occur during the printing process – nothing more, nothing less.

Unfortunately, it’s hard to tell on a monitor how sharp an image will appear in print. We have two fundamentally different technologies at work here, after all. Even so, we can still apply print sharpening reliably using the recipe outlined below.

First, prepare a use-neutral master image at the image’s original resolution (e.g., 4368 x 2912 pixels for an uncropped Canon EOS 5D image). Images should look suitably sharpened on-screen: no visible halos, no artifacts, not too soft, not too sharp. In other words, images should look “just right” on-screen. As an example, the image below shows a 100% crop of the Vermont image from above. I have sharpened the central leaves (the ones in focus) so that they look crisp when viewed on my LCD. However, when printed, the image will appear noticeably soft.

100% crop of image sharpened until the central leaves look fine on-sceen with minimal artifacts. However, the print will appear noticeably soft.

Next, resize a copy of the master image to the native resolution of the printer driver. For example, if I’m preparing a 10″ x 15″ image for an Epson 3800 (which has a native driver resolution of 360 pixels/inch), then I would resize the image to the final output dimensions of 3600 x 5400 pixels. I recommend using the Bicubic method when downsampling (i.e., resizing to a final image size that is smaller than the original image) and using the Bicubic Smoother method when upsampling (i.e., resizing to a final image size that is larger than the original image).

Finally, apply output sharpening. Aim for visible edge halos of around 1/100th of an inch. A halo has a light side and a dark side. Each side should be about 1/100th of an inch wide. How much is 1/100th of an inch? Well, if the target resolution is N pixels/inch, then aim for N/100 pixels wide. Following the above example, 360 pixels/inch translates to a desired halo of 3.6 pixels, or about 3 to 4 pixels wide.

Same crop as above, but with print sharpening.

The result looks over-sharpened on-screen but will print nicely at 360 ppi without artifacts.

You can use whatever sharpening technique you’re comfortable with, such as Unsharp Mask, Smart Sharpen, or High-Pass Overlay. Just preview your image at 100% (or even higher zoom levels) to make it easier to count the number of pixels in the halo you’re creating. This will enable you to adjust the sharpening settings until the halos have the appropriate width. It is critical that you don’t resize your image after applying output sharpening. Why is this critical? Because resampling the image softens it.

400% view makes the halos of print sharpening more obvious on-screen. However, they aren't visible in the print.

Note that this sharpening step will likely make your image look a little crunchy and ugly when viewed at 100% on-screen. Don’t worry. It should appear great when printed, with no visible halos in the print. Not convinced? Try it yourself and judge with your own eyes. You can always fine-tune the 1/100th inch rule above and season to taste.

In summary, output sharpening is a critical step for obtaining sharp, detailed prints. Prepare your use-neutral master image so that it looks suitably sharpened (“just right”) on-screen at the original resolution. Then for output sharpening, start by resizing the image to the final output resolution. Then apply sharpening until you have halos that are about 1/100th of an inch wide.

Tip 5: Don’t Sharpen Smooth Areas

Many images have smooth areas with subtle tonal transitions. Examples of such areas include skies, clouds, and out-of-focus backgrounds. Take care to avoid sharpening these areas throughout the entire editing process. I argue that all forms of sharpening, whether capture, creative, or print sharpening, should be used judiciously with a layer mask to avoid areas of the image that you would like to appear as smooth as possible. This is particularly important if it’s a high-ISO image and there’s some high-frequency noise in the smooth areas to begin with; sharpening tends to accentuate this noise and lead to rougher transitions in the print. (In some images you may want a “grainy” look – like some high contrast B&W prints and especially infrared ones – in those cases masking off the sky from sharpening is not the right thing to do.)

Lake Louise, Banff National Park, Canada - An image with both texture (rocks) and smooth areas (water and fog). It's important to avoid sharpening the smooth areas entirely.

Some experts feel that print sharpening should be done globally across the image, without the use of layer masks, but I disagree. It is certainly easier to apply sharpening globally, but based on my own tests I believe that the best results are obtained through the use of a layer mask to avoid sharpening areas that you want to appear smooth.

A mask (shown in red) used to avoid sharpening the smooth areas.

Tip 6: Noise Can Be a Good Thing

It is common today for both camera manufacturers and photographers to strive for noise-free images. On the other hand, noise – even noise that is deliberately added to an image – sometimes enhances the image when printed on paper. Since noise does not add any real detail or information to an image, how can it possibly be beneficial to a print?

A small crop of the Lake Louise image upsampled to 2x the original resolution and viewed at 100% pixel view. The final print size of the entire image is 16x24 inches. The rocks shown in this crop have “chunky” details surrounded by smoothed-out areas, artifacts of the resampling process.

The digital printing process requires resampling an image from its original resolution to a printer’s own resolution. This resampling process can produce visible artifacts such as blocky edges and areas that appear unnaturally smooth and flat. These artifacts become more noticeable as the image is enlarged, especially with really big blowups. Adding noise breaks up these artifacts and provides the illusion of a more natural, detailed appearance, even though no real detail has been added.

Same crop, but with noise added using the method described below. Resampling artifacts become less noticeable in the print.

Adding noise is particularly effective for images that contain textured areas such as rocks and trees. However, this technique shouldn’t be used for tonally smooth areas (such as skies and fog); those areas won’t exhibit resampling artifacts anyway. A layer mask is useful for confining your application of noise to the areas of the image that need it.

There are many recipes for creating noise. You can do it yourself in Photoshop or you can use specialized third-party noise creation tools (many of which are Photoshop plug-ins). Here’s an easy Photoshop recipe that I use frequently. It’s free, non-destructive (easy to undo), easy to season to taste, works in batch mode via actions, and works with 16-bit images.

Here’s the recipe:

  • Go to the Layer menu and choose New -> Layer …
  • Set Mode to Overlay, check the “Fill with Overlay-neutral color” option, and click OK
  • Set the layer opacity to 50% (shortcut: press the 5 key)
  • Go to the Filter menu and select Noise -> Add Noise
  • Set Amount to something small (in the range 2% to 5%); select Monochromatic; Gaussian (optional); and click OK
  • Go to the Filter menu again and select Blur -> Gaussian Blur
  • Choose a small radius (e.g., 0.2 to 0.4) and click OK

Voila – instant noise. This is a very flexible approach which you can adjust to your needs. You can tweak the layer opacity (to increase or reduce the strength of the noise). You can disable the noise layer to turn off the noise altogether. You can change the noise and blur parameters to create different noise characteristics. You can even apply this step twice, one to make a coarser grain pattern and one with a finer structure. Once you find something you like, bake it into an action. You’ll still need to use a layer mask to limit the application of the noise, however.

Tip 7: Checking Gamut Boundaries and Handling Out-of-Gamut Colors

A printing system reproduces a limited set of colors, known as the “gamut” of the system. Colors that lie outside the gamut boundary and cannot be printed are simply called “out-of-gamut” colors. It is important to note that the gamut depends on all parts of the printing system, including the printer itself, the inks, the paper used, and the selected driver settings.

Above: Indian Paintbrush, Jasper National Park, Canada – When the original image (left) is soft-proofed using a printer profile and the Gamut Warning is enabled, the out-of-gamut colors appear in gray (right). There are other ways to make use of the Gamut Warning (see below).

The preceding paragraph may sound like a bunch of technical mumbo jumbo, but staying aware of gamut limitations is important when trying to coax rich, saturated colors out of an inkjet printer.

As an exercise, go to Photoshop, open a blank white canvas, and assign the ProPhoto RGB profile to it. Fill the canvas with bright red: RGB = (255,0,0). Then go to the View menu and select Proof Setup -> Custom… Select one of your printer profiles in the soft proof dialog box and click OK. Next, go to the View menu again and select Gamut Warning. In all likelihood, the bright red that you were just seeing has now been replaced by the out-of-gamut indicator color (i.e., the color selected in Edit -> Preferences -> Transparency & Gamut…). This means that this shade of red can’t be reproduced by the printing system corresponding to your chosen printer profile.

But why stop there? Let’s go back to the soft proof dialog box and select another profile from the “Device to Simulate” menu: your monitor profile. Now that sounds like a strange idea at first, but try it anyway. Go back to the View menu and make sure that Gamut Warning is turned on. Most likely, you’ll see the out-of-gamut indicator color again. What have we learned? This particular shade of red is a tricky color to work with, because not only can you not reproduce it on your printer, but you can’t even see it properly on your own monitor! Below, I’ve performed this step with a real image:

Soft proof and Gamut Warning enabled using my LCD monitor profile. The gray areas indicate regions of the image that I can't preview accurately on my display (even if they're printable).

Keep in mind that you should always print your images using a real printer profile, not your monitor profile. The purpose of choosing the monitor profile in this little exercise is to show you how the Gamut Warning option can tell you which areas of your image contain saturated colors that can get you into trouble. Soft proofing is often recommended for showing you how your image will look when printed, but the Gamut Warning is an additional aid for focusing your attention on color problem areas during output-specific editing.

For example, you may edit your image using a wide gamut RGB working space such as ProPhoto RGB or Adobe RGB. But this image often is converted to sRGB before being placed on the web. Since sRGB has a much smaller gamut compared to either ProPhoto RGB or Adobe RGB, there is a good chance that some of the colors in your image will be clipped during the conversion from your RGB working space to sRGB. Which colors will be lost? We can use the method described above to find out: just set the soft proof profile to sRGB and enable the Gamut Warning.

That’s what I did for the left image in the example below. The left image shows a screenshot of what I saw in Photoshop when I previewed the original image (which was in ProPhoto RGB) using the sRGB profile with the gamut warning.

Above: Gamut Warning enabled for sRGB (left) and Adobe RGB (right)

As another example, printing performance may degrade slightly when printing colors that lie near the gamut boundaries. For example, when printing on PK papers with the Epson 3800, prints tend to get a bit “grainy” when pushing the yellow and red gamut boundaries. The 3800 can print very saturated yellows and reds indeed, including colors that lie outside the Adobe RGB color space; it’s just that the most saturated yellows and reds appear less smooth. I’ve discovered through experimentation, however, that the 3800 has no trouble with printing yellows and reds that lie within Adobe RGB.

How do I make use of this information? Whenever I’m preparing an image for my 3800 to be printed on PK paper and the image contains saturated yellows or reds, I set the soft proof profile to Adobe RGB and turn on the Gamut Warning (see the right image in the example above). If any of these colors turn into warning indicators, then I know I’m likely to get some graininess. Editing those yellows or reds (e.g., via selective desaturation) until the gamut warning disappears solves the problem. Another way to address the problem is to convert the image to Adobe RGB; this clips the offending yellows and reds to the boundaries of the Adobe RGB gamut. This method is simpler but offers less control.

What happens when we try to print an image that contains out of gamut colors? Well, those colors can’t be printed (by definition!) so we have to substitute other colors that do fall within the gamut of the printing system. This color substitution is called gamut mapping. There are two common ways gamut mapping occurs: (1) we can allow the printer profile to perform the mapping for us, or (2) we can edit the image directly, usually with selective adjustments). Let’s take a brief look at both approaches.

Letting printer profiles automatically handle out of gamut colors is easy. The results are often pretty good and not much work is needed. All you have to do is use the soft proof (with the appropriate printer profile) to choose a rendering intent, usually either Perceptual or Relative Colorimetric. You can read more about rendering intents and soft proofing in an earlier NatureScapes.Net article.

The problem with letting printer profiles perform gamut mapping, however, is that they don’t take your image content into account. If you think about it, it’s pretty clear that they can’t: the nice folks who built your printer profiles certainly didn’t consider your specific images. Consequently, you may find you’re your profiles’ automatic gamut mapping works nicely with some images but poorly on others.

A solution to this problem is to take gamut mapping into your own hands. This is actually easier than it sounds and here’s a recipe for getting it done.

First, select your printer profile in the soft proof dialog box, set the rendering intent to Relative Colorimetric, enable Black Point Compensation, and enable the Gamut Warning as described above. Here’s an example of what I see on my screen when soft proofing my Indian Paintbrush image using the Epson UltraSmooth Fine Art printer profile for the Epson 3800 printer:

Soft proof using the UltraSmooth Fine Art profile for an Epson 3800. The saturated reds and greens are out of gamut.

Next, observe that the out of gamut colors are usually pretty saturated or dark. We can tame these colors by desaturating or lightening them. One way to accomplish this is to add a HSL Adjustment Layer. Go to the Layer menu and choose New Adjustment Layer -> Hue/Saturation. Try decreasing Saturation by a few points and/or increasing Lightness by a few points. Keep adjusting these values until all the Gamut Warning indicators disappear. In this example, I set Saturation to -5 and Lightness to +5:

 

 

 

 

 

 

 

 

Global HSL adjustment (-5 saturation, +5 lightness)

Ugh! What happened to the image? It has become rather pale and washed out, because the HSL adjustment layer is currently working on the whole image. Don’t worry; we’re going to fix that in the next step. Click OK to exit the Hue/Saturation dialog box.

The result of applying the global HSL adjustment. Overall the image has become lighter and paler.

Hold down the option/alt key and click on the “Add Layer Mask” button in the Layers palette. This step creates an inverted layer mask that temporarily undoes the HSL adjustments; the Gamut Warning indicators should reappear. Select a soft brush, set the brush opacity to a moderately low value like 30%, and begin painting into the layer mask over the out-of-gamut colors (i.e., the highlighted areas). Notice that we are now performing a selective desaturation and/or lightening, because the effect of the HSL adjustment layer is gradually getting added back in the painted areas. By using a brush opacity around 30%, we can paint lightly over some areas (e.g., a single brush stroke) to make a small HSL adjustment and more heavily over other areas (e.g., multiple brush strokes) to make stronger HSL adjustments.

As you progress, the Gamut Warning indicator should gradually disappear, until you finally see an image without any indicator marks at all:

 

 

Above: Final soft proof (left) with HSL adjustments applied selectively using a layer mask (right). The Gamut Warning is enabled, but now all colors lie within gamut.

At this stage, I usually apply a fairly generous Gaussian blur to the layer mask to smooth out my selective edits. For this example, I used a radius of 50 pixels. The final image (converted to sRGB for display) and the layer mask are shown above. Recall that lighter pixels in the mask represent areas of stronger desaturation and/or lightening:

Now we have no more out-of-gamut colors!

Tip 8: Use Standard Test Images to Troubleshoot

When you run into printing quality problems, such as prints that are too dark or whose colors are off, it can be tricky to track down what’s going wrong. This is because printing systems are complex beasts with many variables involved.

In these situations, I highly recommend using a standard test image, such as the PDI Test Image here:

http://www.drycreekphoto.com/tools/test_images/DCP-TestImage-Small.zip

PDI Test Image

Another good one is below, even though it was originally designed to test printer profiles. The first link provides the target; the second link offers suggestions on what to look for in the test prints.

http://www.outbackprint.com/printinginsights/pi048/essay.html

http://www.outbackprint.com/printinginsights/pi049/essay.html

Outback Photo test image

The Outback Photo test image contains a small version of the PDI Test Image.

These test images have some useful properties:

  • They are sized to fit on a standard letter or A4 sheet, thus making it suitable for small test prints.
  • They contain both synthetic and natural imagery. The natural images represent a wide range of commonly-occurring colors.
  • For the first target (the PDI Test Image), the natural imagery almost lies entirely within most printer gamuts, particularly when printing on PK papers. Thus you don’t have to worry about how your profile handles out-of-gamut colors.

There are many ways these test images can be used in practice. Here are three examples.

Example 1: Try a screen-to-print match. Print the test images with the Relative Colorimetric rendering intent and Black Point Compensation enabled. If you get good results (i.e., a good screen to print match), then it’s likely that:

  • your monitor is set to the appropriate brightness (since tones seem to match between monitor and print)
  • your printer profile for this paper is ok (since you get good tone and color matches)
  • your printer driver settings are ok (for the same reason)
  • your display profile is fine (again for the same reason)

What can we conclude? If these test prints look good but prints of your regular images are off, then there’s probably something wrong in how those images were edited or processed.

Example 2: Compare against a reference print. The idea here is that someone (a “printing expert”) supplies you with a physical hard copy print of a test image. You keep it in the dark and well protected for reference purposes. Next, you make your own test print, using your own printer configuration. After allowing the print to dry, you compare your test print against the reference test print. They should match. If they don’t, then something is likely amiss with your printer settings (e.g., your software driver settings) or perhaps your printer profile. It’s possible there’s something wrong with the printer itself, but that’s less likely.

Example 3: Comparing papers. Printing the same test image on different papers will let you compare the strengths and weaknesses of the various papers (especially PK vs. MK papers). These are good test images to use since many colors and tones are represented.

Tip 9: Shake It Up!

Do you print infrequently? Do you let your printer sit idle (and perhaps powered off) for weeks at a time, then suddenly need to reel off a dozen prints? If so, you may find it helpful to perform the following 3 steps before you start the new print job.

Step 1: Remove the ink cartridges from the printer one by one and shake them gently side-to-side four or five times. This step improves ink flow by counteracting any settling of the pigment particles that may have occurred during the idle period; the result is better color accuracy.

Step 2: Run a nozzle check (and a head clean if necessary); you don’t have to worry about this step if you have a printer that checks itself for nozzle clogs.

Step 3: Run a print head alignment. This step usually can be done from either the printer unit itself (i.e., using the printer panel’s buttons) or from the software driver; consult your printer’s user manual for details.

I would recommend performing these steps whenever your printer has gone for at least 2 weeks at a time without making any prints.

Tip 10: Presentation Counts

No matter how much we talk about cameras, lenses, printers, inks, and papers, everyone knows that it’s the image that counts. But it’s not the only thing that counts, and sometimes the image alone isn’t enough.

Presentation matters. Careful and elegant presentation of your prints conveys a more polished, finished piece of work. This is even more important if you’re looking to sell your work.

The topic of presentation is too complex to describe completely here, but the good news is that there are many nice presentation options. They can range from informal scrapbooks and albums, to more formal portfolio boxes, and to matted and framed prints. Let’s take a brief look at portfolio boxes and matted prints to understand some of the issues involved.

Twelve 9.5” x 13” prints stored in a Digital Print Folio

Portfolio boxes contain a collection of prints, usually between 10 and 20. The prints are sometimes matted, but more often they are not. It is common to store prints in these boxes separated by interleaving tissue, especially when using delicate matte papers that are prone to flaking or scuffing. In any case, using interleaving tissue is a good idea because it prevents prints from sticking to each other. Information that’s worth putting in a portfolio box includes a cover page, an artist’s statement, a description of the portfolio itself, and perhaps some relevant technical information.

There are many types of portfolio boxes one can use. For less formal portfolios, I like to use the “Digital Print Folio” (shown above) which is a nice thick folder available in sizes to accommodate the standard inkjet sheet sizes. For special portfolios, I prefer the “Gallery Portfolio Boxes” which have a clamshell design. These can be obtained from many places, such as Archival Methods.

Now let’s see how a portfolio box might affect the printing process. It’s clear that prints in a portfolio box are designed to be handled and inspected in the hand. Thus, I would recommend leaving at least a 2-inch border all around the image. A nice big margin makes it less likely for the printed surface to get damaged by fingerprints, dents, and dings. Incidentally, a large margin means you’re less likely to get a head strike, at least when using the smaller format printers. (A head strike occurs when the print head collides with the paper edge or surface, usually leaving a nasty ink smear.)

The choice of paper is particularly important for portfolio-boxed prints, because these prints will be held and viewed closely. My experience has been that heavyweight papers with a nice surface tend to convey a more positive impression than thin papers (such as most resin-coated papers).

Another issue related to paper choice is glare. Prints that are designed to be held in the hand can be viewed anywhere, at any angle. One of the reasons that many photographers prefer using PK papers is the rich color saturation and black density achievable on such papers. But this advantage actually disappears under many lighting conditions, because glare off the surface actually reduces saturation and contrast. A demonstration I often run is to show two prints side by side of the same image, one printed on Epson Velvet Fine Art (MK paper) and the other printed on Epson Premium Luster (PK paper). Under a few specific lighting and viewing conditions, the blacks on the PK paper are much, much deeper. But surprisingly, under ordinary conditions, especially when comparing the prints while holding them in the hand, the blacks on the MK paper are much deeper. This may not be a critical issue, but it’s worth keeping in mind.

Yet another issue to consider is image size. It’s possible to have portfolios printed on 17″x 22″ sheet paper, but that’s not a very convenient size to handle! Letter-sized sheets are much easier to manage and offer a more intimate viewing experience, since they encourage closer inspection. However, you may feel the image size is too small. Sheet sizes just a bit larger than letter-sized are nearly ideal in my opinion: small enough to handle conveniently and hold comfortably in one hand, yet large enough to provide a decent image size. For one of my portfolios, I found that a good size was obtained by taking 13″x19″ sheets (which are easy to find) and cutting them in half to create 9.5″x13″ sheets. This is an uncommon size, but one that I found works great for portfolios: not too big, not too small, and a nice aspect ratio. Other more standard options include 11”x14” and 11”x17” sheets.

A 12" x 18" image (on 13" x 19" paper) double-matted to 19" x 25"

Now let’s switch gears and discuss having prints matted and framed. This article isn’t about the framing process, but I do want to encourage you to try getting some of your best prints matted and framed if you haven’t tried doing so yet. You may be surprised how much the viewing experience is enhanced. You can have the framing job done locally. You can also order supplies online (e.g., from American Frame, among many other good places) and assemble the materials yourself, as I did in the examples above and below.

Matted and framed print (almost ready to ship)

Now let’s consider some of the ways that a matted and framed print might affect the printing process. First of all, these prints don’t move around much: they’re supposed to be hung on a wall and viewed from essentially a fixed location. If the lighting is reasonably controlled, you can minimize the glare issue that came up with portfolio box prints (see above). Since the prints won’t be held in the hand, the choice of paper surface is less important. Using a thinner paper is fine, although I still recommend using thicker ones because they’re easier to mount and less likely to buckle.

I recommend leaving at least a 1″ margin around the image; doing so makes the image easier to mat, since there will be enough room for the mat to hold down the edges of the sheet comfortably. For thick papers, you can often get away with a ½” margin. In the first example above, I printed a 12”x18” image on a 13”x19” sheet of Velvet Fine Art, which is 19 mils thick; this left a ½” margin on each side.

Wrap-up

Give yourself a nice pat on the back for making it this far! Let me wrap up the article with a quick summary and some suggestions on how to apply these tips to your prints. We’ve covered paper choice and presentation (Tips 1 and 10), tonal range (Tips 2 and 3), detail and texture (Tips 4 through 6), gamut problems (Tip 7), test charts and troubleshooting (Tip 8), and maintenance (Tip 9). Don’t feel obliged to apply every single tip to every one of your prints. For example, you don’t need to worry about optimizing the black point (Tip 3) for low-contrast images.

One way to get started is to use these tips as a checklist as you’re preparing your prints. I hope that with experience you will learn to recognize which tips matter the most to your own images, and perhaps you will improve on the methods I outlined to get even better results!

Happy printing!

About the Author

Eric Chan is a computer scientist at Adobe Systems, where he conducts research and develops software for processing digital photographs. His primary research interests include real-time rendering algorithms and graphics architectures. Eric is an enthusiastic nature photographer and spends an unusual amount of his free time peering through lenses, experimenting with papers and inks, and figuring out how to squeeze every last ounce of quality out of his printer. To learn more about Eric and to see some of his photographs, please visit http://people.csail.mit.edu/ericchan/ and http://people.csail.mit.edu/ericchan/photos/.

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