Printing With Profiles in Photoshop CS
|
Please see diglloyd’s other articles at diglloyd.com. |
Table of Contents
Introduction
Setting up Photoshop color preferences
Color space of your original image
Printing your image
Step 1 Make a duplicate
Step 2 Page Setup
Step 3 Image Size
Step 4 Sharpen
Step 5 Print With Preview
Step 6 Print
Step 7 Examine the Print
Appendix A--Gamut, color spaces and profiles
Overview
This article steps the reader through the process of printing using color profiles in Adobe Photoshop CS/CS2. Step-by-step screen shots are provided at every step. Each screen shot is annotated, and text explains why each step is needed. The screen shots are all from Mac OS X, but Photoshop dialogs on other platforms are very similar, and the concepts do not change. If you don't use Adobe Photoshop, the concepts will be the same in other programs, so reading the article should still be helpful. The screen shots from the Epson printer driver are significantly different from Mac OS X to Windows; this article will be updated in the future to add the Windows screen captures.
This article is for you if you:
- want to get accurate color in your prints.
- don't understand how or why color profiles are used.
- are not sure how to print your files to get accurate color from your printer.
- need a handy reference on a step-by-step printing procedure.
It covers the following topics related to these goals:
- An introduction to color spaces and profiles.
- An introduction to calibrating and profiling your computer monitor.
- Setting up Photoshop color preferences.
- Color space of your image, and why it's important to have one.
- Step-by-step printing instructions
The step-by-step instructions include:
- making a duplicate
- Page Setup
- Image Size and resolution
- Simple sharpening
- Print with Preview dialog and its Color Management options
- Print dialog and setting the printer settings
This article explains how to print with accurate color to an Epson Stylus Pro 7600, Styles Photo 1280, or any similar printer using Adobe Photoshop CS/CS2. If you don't use Photoshop, the same principles apply, assuming your program allows you to manage color properly. Even if you don't print very much, the concepts in this article should still be useful in other areas.
While reading this article, it is helpful to understand what a color space and color profile are. See Appendix A--Gamut, color spaces and profiles. However, may safely skip that section and simply follow the step-by-step instructions in this article.
Not all printers are suitable for printing a quality color photograph. Those designed for business graphics for example, will not produce accurate color, as they may use only 3 or 4 ink colors—not enough for accurate color.
For a long time, Epson has been the photographer’s choice for high-quality photographic printing. Its "Stylus Photo" line (emphasis on Photo) has appealed to serious amateurs, and its Stylus Pro line has targeted professional photographers. However, Canon and Hewlett Packard are now competing with Epson in these markets. In general, a printer suitable for high-quality photographic prints should have at least six different inks. The additional inks allow a wider color range and more accurate color within that range. Ideally, the inks should be in separate cartridges so that running out of one color does not mean discarding the whole cartridge. But that is an issue of cost, not quality.
A printer that ships without high quality printing profiles is next to useless for printing color photographs. If it has a suitable ink set and printing head setup, it may be amenable to getting a custom profile made for it. However, any manufacturer that does not provide printing profiles for its printer should be avoided.
The author’s experience is with Epson printers over a number of years. While Canon and HP no doubt now offer some excellent and appropriate printers, the author cannot confirm or deny this from personal experience.
The Epson Stylus Photo series printers come with a set of color profiles for the printer. These profiles are quite good, especially the ones for the wide-format printers (9600, 7600, 4000 series). If you are using an Epson 9600 or 7600, profiles are available on the Epson site which were created to exacting quality by color expert Bill Atkinson. These are the best printer profiles I've used, and a compelling reason to buy one of these printers if you're looking for accurate color—you won't find a better profile. You may also choose to have your own custom profiles made, which is a necessity if you are using a paper for which Epson doesn't supply a profile.
Read section 2 to learn how to set up your color preferences and to verify that your image has a color space assigned to it. Read section 3 for a step-by-step outline of how to print your image. In most cases, screen captures are shown. Where there there are significant differences between Photoshop CS and Photoshop CS2, both screen captures are shown, with the Photoshop CS version to the left or above the CS2 version. All screen captures are from the Mac OS X version of Photoshop CS and CS2.
2. Setting up Photoshop color preferences
Before you begin, prepare your Photoshop color preferences as detailed below. There are many possible configurations, but if you are unsure, start with these settings.
2.1 Verify that Photoshop Color Settings are correct
Choose Color Settings...:
| Photoshop CS | Photoshop CS2 |
|
 |
The following dialog appears. In Photoshop CS2, you may have to click the More Options button to see all the choices (not shown below. Configure the settings as shown:
Photoshop CS |
2.2 Verify the color space of your original image
Prior to printing your image, you should verify that it has a color space assigned to it. Open your image in Photoshop. If it has an embedded color space saved within the file, Photoshop will automatically display it appropriately. But if it has no color space, Photoshop will ask you when you open it (assuming you checked (enabled) the Missing Profiles: Ask When Opening setting as shown in the Color Settings dialog). The Missing Profile dialog will appear:
If you click Cancel, or this dialog did not appear, you can still assign a profile later. If you know the document's profile, select Assign Profile and choose the appropriate profile (Adobe RGB is shown above). If you're not sure, you may want to defer making a choice; you could make several duplicates of the document once it is open, and assign sRGB to one and AdobeRGB to another to figure out which color space works best for the image. Most of the time, the correct profile will be one of those.
Note that having to assign a color profile should be a rare event—you should be saving all your images with embedded profiles so that this error-prone step may be avoided entirely. Images saved for the web should usually be in the sRGB color space.
If there is no color space ("untagged RGB"), then you'll need to make a best guess as to the correct one. Check the lower left corner of the image window to see (you may have to choose Images). In this case the image is in the sRGB IEC61966-2.1 color space. The name is not important; the fact there there is a profile is important.
| Photoshop CS |
 |
Photoshop CS2 |
 |
If the Document Profile reads Untagged RGB, then it has no profile. You will need to assign one (not convert
to one). The Assign Profile... command is found in the Image menu in Photoshop CS and the Edit menu in Photoshop
CS2:
| Photoshop CS | Photoshop CS2 |
|
 |
The Assign Profile dialog appears. First try assigning sRGB (shown below) then AdobeRGB. These are the two most common color spaces. Choose the one that seems most accurate and natural, not the one which has the most saturated color or "pops".
Now that your image has a color profile, make any desired edits (preferably using layers) and save it as your master image. You are now ready to print it.
3. Printing your image—step-by-step
Your master image is your original image, together with all its layers (if any). If you are using Photoshop without layers, you should either have an extremely good reason to do so, or invest the effort to learn how to use them—they are indispensable because they allow you to “edit” your image without making changes to the original. You should almost never adjust the original image itself; instead always use an adjustment layer to make any change(s).
Duplicate the image (Image => Duplicate). Be sure that Duplicate Merged Layers Only is checked:
It is the duplicate that we will print. Do not flatten the origina and be sure to close the original window after you make the duplicate. This frees up computer RAM, and ensures you won't accidentally overwrite the original file.
Decide what size you will print the image. This may be the same every time, or it may vary. I use roll paper, so to minimize paper waste, I defined a number of paper sizes in 1-inch increments. Let’s assume we are are using roll paper and want to print an image as wide as possible (24 inches on the Epson 7600) and 10 inches high. I have never gotten full-bleed (borderless) printing to work correctly on the Epson 7600, in spite of conversations with Epson technical support and Epson’s claims to the contrary.
The maximum image width is actually 23.6 inches. But the paper size is 24 inches. Choose File => Page Setup.... The Page Setup dialog will appear:
First select the correct printer (7600-RollPaper-Margins in this example), then choose Custom Paper Size:
The Page Setup dialog will change to show the Custom Paper Size choices:
Now define your new paper size. It is a good idea to be consistent in how you do this; I always define my paper to be 24 inches wide for the Epson 7600 roll paper, and simply change the other dimension. In reality with 24" roll paper, the paper is always 24" wide, so it's best to keep your paper size definitions set to a Width of 24". I never change Orientation, preferring to simply rotate my image to best fit the paper size (just prior to printing it). If you don't follow this convention, you may find it confusing to have to combine the paper size with landscape/portrait page setup and the actual orientation of your image—it's not wrong, just confusing.
Decide if you want white space around your image. For example, for matting and framing, you may want a 1 or 2-inch border around the entire image. In this example, we are using an Epson 7600 with 24-inch-wide roll paper. If we desire a 1-inch border on each side, then our maximum printable area is 22 inches wide. We'll need to make the width of our image be 22 inches. This will leave 1 inch of blank paper on each side.
To avoid paper waste (at least on roll paper) you may want to rotate your image 90 degrees to fit the width of your paper. For example, if you are printing a 16 X 20 image on 24-inch-wide roll paper, you'll want to send a 20-inch-wide image to the printer. This may mean rotating it 90 degrees. You'll save 4 inches of paper this way. If your image is, say, 16 X 28 inches, and you're printing on 24-inch roll paper, then you have no choice—the image will need to be 16 inches wide and 28 inches tall; you'll have a 16-inch-wide image with 4 inches of blank paper on each side.
Now, ensure that your image is a resolution that will produce the desired width (in this example printing 22 inches wide on 24-inch paper). Unless you are using advanced resampling techniques or special software, it is perfectly fine to just let the printer driver resample the image as necessary, so leave Resample Image unselected.
The key point is to make sure that the Width of the image is the width of the printed image you desire, regardless of what the Resolution box says. The Width value is the actual printed size of the image on paper that you can measure with a ruler. Personal experience shows that on Mac OS X, the Epson driver will not print properly on 24-ich roll paper with a Width value larger than 23.6 inches. This is true even following Epson’s convoluted workaround for this problem found detailed in their tech notes.
Now is the time to add the border to your image. We'll leave the Width value alone, because a 22-inch-wide image on 24-inch paper will leave an inch of white space on each side simply by virtue of not printing anything on that area of the paper.
Assuming a 1-inch border is desired on the top and bottom, we'll need to add two inches to the canvas Height to ensure that there is at least 1 inch of paper on the top and bottom of the printed image. Change the canvas Height from 27.5 to 29.5 inches. Unless you want the border to be non-white, make sure Canvas Extension Color is White. Also, make sure Anchor is centered as shown:
If you're printing with roll paper on a printer like the Epson 7600, there are always several wasted (blank) inches of paper on the top of the image. So you can skip the 1 inch on the top, and just add 1" to the bottom for a total canvas Height of 28.5 inches. In this case, be sure Anchor is as shown:
When an image is printed on an inkjet printer, there is a certain amount of “ink spread”; the ink absorbs into the paper by varying amounts depending on the paper being used. Glossy papers have less ink spread and matte papers have more. Therefore, sharpening will vary according to the paper (and printer and ink) used. It will also vary by the size of the image, the image content, etc. If you are printing to a laser-based printer such as the Cymbolic Sciences Lightjet, then there is no ink spread, and the amount of sharpening will be different.
Sharpening is as much an art (and personal preference) as a science. An entire book could bewritten on different sharpening techniques. For this example, we'll do something much simpler, which in most cases will produce very good results with minimal effort. Be sure your image is flattened as previously mentioned. Then choose the Unsharp Mask… command:
The Unsharp Mask dialog appears:
You'll usually want a Radius value between 0.5 and 2.2 pixels, and a Threshold between 0 and 10. Vary the Amount until the image looks a little too sharp, but not harsh. This is as much a matter of taste as anything else. You may want to print a variety of samples with different Amount/Radius/Threshold values to get a feel for how the actual printed result changes.
If the image is RGB, you have sharpened all channels. The next step is optional, but helps eliminate any colored speckles along high contrast edges caused by the sharpening. Choose Fade Unsharp Mask…, then click the OK button.
 |
 |
If your image is in the Lab color, sharpen the Lightness channel only and then this step becomes unnecessary. Of course, if you’re working in Lab color, you should know what you are doing already!
If this is an image you intend to print repeatedly, now is a good time to save this sharpened and sized copy for future use. Choose a name for the copy. For example, if the original master image is Bird.psd, you may want to save the copy as Bird-16X20-Print.psd. Use whatever nomenclature makes sense to you. Just be sure not to save over your original, master image.
The image is now sized, sharpened and otherwise ready to print. Now you need to know what type of paper you are printing on, and which profile is correct for it. If you don't know this, stop and find out. The paper you are using should be known to you, since presumably you purchased it. The printer profile may not be so obvious.
Choose Print With Preview… from the File menu and the Print dialog appears. It is slightly different in Photoshop CS and Photoshop CS2, so please refer to the appropriate example.
Photoshop CS
 |
Photoshop CS2  |
If at this point the size or page setup are wrong, cancel out and fix them.
Note that the Source Space is Adobe RGB (1998); this is the color space of your image. The print will be made on Epson Premium Luster paper at 2880 DPI, on my Stylus Pro 7600. The printer profile is called 9600 PrmLuster PLU2 Std v3.icc (the Epson 7600 and 9600 use the same profiles). You will need to determine, for you printer and particular paper which is the correct profile.
A key point about this dialog is that Photoshop will convert your image from its color space (Adobe RGB (1998)) to the printer's profile (9600 PrmLuster PLU2 Std v3.icc) during printing (Color Handling: Let Photoshop Determine Colors). This is why the printer driver must be set to No Color Adjustment (read further to see this shown). Otherwise, conversion is done twice, which will ruin the result. There are other ways to accomplish the same result; do it this way until you understand the process.
The rendering Rendering Intent and Black Point Compensation generally work best with one of the following choices. Certain images may print better with one choice over another, but generally Perceptual with Black Point Compensation off is a good starting point for most images. The settings shown below are for Photoshop CS; Profile is Printer Profile in CS2:
Click the Print… button in the Print With Preview… dialog and the following dialog appears:
Ensure that the correct printer is chosen. In this case my printer is named 192.168.1.27(IP:Roll Paper). The Presets popup shows any previously saved settings that I created. In this case, it shows 7600-PremLuster-2880.
Next, make sure the Print Settings and Color Management settings are correct.
Media Type must match the paper being used. The tricky part here is that the dialog allows you to choose any paper combined with any profile—you are free to make the wrong choice.
Advanced Settings must match exactly those settings used when the profile was made. Do not use Automatic or Custom. Use only Advanced Settings, as this is this the choice that allows you to set the options exactly the same as were used for creating the printer profile:
Color Management must be set to No Color Adjustment. If you don't do this, the color will be adjusted more than once or not at all and the results may be hideous indeed.
Always double-check that everything looks OK, by viewing the summary:
If this is a new selection of settings that you will likely use again, be sure to save them for future use:
Choose a name that will be meaningful to you, and consistent with other names you have chosen. I have an Epson 1280 and 7600, so my names are of the form 7600-PaperType-DPI. For example, I might have 7600-PremLuster-2880, 7600-PremSemiMatte-2880, 1280-PlainPaper-360, etc.
Finally, the moment has arrived—click the Print button to send your image to your printer.
3.7 Examine the print
With the finished print in front of you, consider the lighting in your space—to check for accuracy in the print, you ideally need a 5000K viewing box which produces color-balanced light. Lacking that, sunlight is a possibility or even halogen lighting. Just keep in mind that without a color-balanced light source, you can't necessarily see any subtle issues with color.
If the print is not what you expect then there are several possibilities:
- your display is not calibrated and profiled correctly.
- you made a mistake in printing the image. Try again to see if you get the same results.
- you used the wrong printer profile, a profile for a different printer or different paper.
- the profile is of poor quality and does not accurately characterize how the printer actually behaves.
To check whether you can make a print that matches what you see on screen, I recommend downloading a test image in the Lab color space. You should be able to produce a print that is a close match for what you see on your screen. One site I recommend for this is hutchcolor.com. A good image to begin with is Lab ramp.tif, which will reveal how good your printer profile is. Most printers cannot produce a truly neutral gray scale ramp, and this image will reveal any shortcomings in your profile. For seeing how neutral your monitor is, use White_Balance_RGB.tif, but do not assign a color profile—choose Leave as is (don't color manage) when Photoshop asks.
Appendix A--Gamut, color spaces and profiles
There is no such thing as red or green or blue or any other color in the sense of it being absolutely defined and perceivable in the same way by different individuals. Every human being perceives color slightly differently (and a signficant percentage have varying degrees of color-blindness). We tend to agree that various shades of color are appropriately called red or green or blue, but with a great deal of slop allowed before we reject something as no longer being that color.
The number of distinct colors which can be seen or represented is called a color gamut. Human vision is capable of a very large gamut, much larger than can be recorded by photographic film or digital cameras (with the exception that most digital cameras can record infrared or ultraviolet light also). When you take a picture on film, colors you perceived in the scene may mush together on the film and become indistinguishable; this is because the film simply cannot distinguish certain similar colors! The same is true for digital cameras. Human vision is incapable of perceiving infrared or ultraviolet light (or for that matter gamma rays!). (The is an exception to this—a few rare individuals can see ultraviolet light after having the lens in their eye replaced for medical reasons). Yet film or digital can see such colors. Thus, the gamut of color available to film or digital or each human eye is different in every case. Even for film or digital cameras, each film or model of digital camera has a slightly different gamut. The same is true of your computer monitor or printer or television set. If you have three identical computer monitors, each one will display color slightly differently! This is why it is important to calibrate your computer monitor.
As a practical matter, there are reasonable subsets of color that are useful to humans. Initially, color printing relied on cyan, magenta, yellow and black inks, each applied on the paper, to achieve a color image. The gamut of such a printing process was and still is somewhat limited—which is not to say that it is note useful and enjoyable. Today, we have many types of printers, each with its own gamut.
As computers evolved, it became necessary to make choices as to what gamut was actually useful. Depending on the task involved, and the type of print to be made, a wide gamut, capable of representing a very large range of colors, or a small gamut, capable of a smaller range of colors, might be appropriate. Why not just always use a large gamut? Because each pixel (individual dot) in a digital image has a fixed number of possible values. In order to represent a wide range of color, the intermediate values must therefore span a larger range. For example, in an 8-bit RGB image, there are only 256 possible values for the red component. Thus, only 256 possible values for red are available. The human eye can perceive thousands of shades, many of which are not printable. If reds are particularly important to an image, the choice may be made to interpret the red component with a limited range, but very fine gradations. Today, computers have enough memory to work in 16 bit color (16 bits each for red, green and blue), and a wide color gamut space can safely be used for any image, though the tools to work in 16 bit color are still improving.
Thus, the notion of a color working space has evolved. Each such color working space makes choices about the range of colors possible, and thus, the fineness or coarseness of the intermediate values. The advent of 16 bit images improves this situation significantly, since 16-bit images allow 65536 values for each of the red, green and blue components. In recent years, support for 16-bit color has become much more widespread, though in many cases, it is less important than one might think.
A digital image contains values for each pixel. Typically images are RGB eg they consist of a red, green and blue component, either 8 or 16 bits (256 or 65536) values each. By themselves, these values offer only a rough idea of what they might represent—that is they have no fixed meaning unless the color working space is specified. Typical color working spaces include AdobeRGB(1998), sRGB, and Lab. Of these, Lab is a very large gamut color space which is used internally by Photoshop whenever a device-independent color-space is needed for performing calculations; it's specifications derive from actual studies of human vision. It may be thought of as standard, or reference space to which the other color spaces are relative. Working in Lab is somewhat different and non-intuitive to most people, but it has certain advantages because it separates brightness (luminance) from color.
Considering the above, you ask a printer to print an RGB value of 220, 100, 37, that such a request could produce virtually any color without also specifying what color space the values reside in. It's like giving coordinates, without saying whether they are metric or English, or linear or angular! This is why you get very strange prints if you don't tell print by correctly specifying the color profile of the printer.
A color profile characterizes how color and/or grayscalue values are displayed on a computer monitor, a printer or any type of display device by relating its gamut of colors in its color space to values in the Lab color space. When printing, Photoshop, or similar application, can alter the values sent to the printer or screen such that the color that is produced is as close as physically possible to the correct color. Obviously a good profile is one that is highly accurate, and a poor one is one that is crude in its mapping of color/grayscale values.
A CRT monitor, an LCD display a print from your printer, an LCD projector all display color and grayscale tones differently--sometimes a little bit differently and sometimes a great deal differently (and at varying degrees of accuracy). The job of a color profile is to characterize how various colors display on that particular device. For example, a pure red may display as something that looks red on a CRT, orange on a print, and maroon on a particular LCD. The actual color perceived by the viewer is a physical property of the output of the device that produced it. By using a color profile, Photoshop can change the values sent to the screen or printer such that they mimic, as closely as possible, the desired color.
Appendix B--Calibrating and profiling your display
Your computer display (monitor) is almost certainly either a CRT (cathode ray tube) or LCD (Liquid Crystal Display). Each display, even the exact model from the same manufacturer, displays color slightly differently. Some or more or less accurate than each other. They vary in brightness and contrast. When you make modifications to a digital image you need a display which accurately displays the colors in your image.
The solution is the calibration and profiling of your computer display. Calibration is the process of setting your monitor to a known state. Profiling means describing the range and accuracy of colors on the display, once calibrated.
To calibrate a display requires first setting the brightness, contrast and any other settings such that they produce as accurate color as possible. A quality monitor has controls over brightness and contrast ratio and sometimes other parameters that affect color and grayscale rendition. Read your manual for details. However, LCD monitors typically have only a brightness control.
Set your display controls to the settings recommended by the manufacturer for photo applications. Then choose a brightness and contrast setting (if available), that you are comfortable working at. You should leave your monitor at these settings until such time as you create a new profile for it; any change to these settings invalidates the monitor profile (read on).
Now it's time to profile your monitor. If you have an Apple Powermac, Apple has built in simple profiling facility. Open your system preferences and click on the Color tab. If you have multiple monitors, do this for each monitor. Then click on Calibrate... and follow the directions (choose Expert Mode).
Calibrate your monitor for a gamma of 2.2 (typically the native gamma of the display). Do not use Mac Standard. It is not appropriate for a number of reasons. Choose a white point of D65 (6500K):
When done, a color profile will be created describing the calibration you've done. In truth, the profile assumes that the calibration is accurate; it may not be. For an accurate profile, you'll need an additional hardware device, such as that sold by Gretag-Macbeth. However, the author has found that certain LCD monitors (such as Sun Microsystem's 24.1-inch LCD) are very accurate and can be safely used without hardware profiling.
Appendix C—A note on printer profiles
The term Printer Profile is a bit misleading because it really means "a color profile for a specific printer, paper, ink, and printer setting combination". For example, Epson provides the following profiles with the Stylus Photo 1280:
Unfortunately, Epson does not specify at what DPI (1440 or 2880) these profiles were created with. This is not as good as a profile which specifies the exact printer settings used to make the print from which the profile was generated. If you have no choice, you just have to hope that the profile is "close enough", or have a custom profile made. By comparison, color expert Bill Atkinson is careful to give the exact printing parameters he used to create his profiles—and he supplies both 1440 and 2880 DPI versions of his profiles for most papers.
If your printer was designed to print high-quality photographs, it should have come with printer profiles, and these should have been installed along with the printer driver. If you bought a printer, and there are no profiles for it, it is probably the Wrong Choice.
Contact: email diglloyd a comment on this article.
See also: |
||||||||||
You’ve just enjoyed a free digloyd.com article.
Diglloyd.com also offers paid articles/reviews,
whose depth and breadth you’ll rarely find anywhere else—and which you can rely on for purchasing
decisions.
|
