Producing Colour-Accurate Prints

As we’ve covered printer drivers in Using Printer Drivers and Editing Software, this section is devoted to using paper profiles. When you buy an inkjet printer, the driver software contains pre-loaded ICC profiles for papers suitable for use with that printer. Paper profiles can also be found in the Technical Support section of the printer manufacturer’s website under Inkjet Printer Drivers. Most manufacturers update them regularly as new products are released and existing products are improved. However, only papers produced by (or for) the printer manufacturer and sold under the manufacturer’s brand name are profiled.

Printer drivers come pre-loaded with ‘canned’ profiles for the manufacturer’s papers that can be used with the printer’s ink set. This makes it easy to choose the correct profile setting.

In most cases, the ‘canned’ profiles supplied with the printer will yield good results with the selected paper – provided all other steps in the workflow are under control. However, they may not be adequate for photographers who want to print on ‘fine art’ papers from other manufacturers. If an ICC profile is available for the paper, loading this profile should produce acceptable print quality. Without an ICC profile, you have to rely on guesswork, which wastes time and paper.

Applying ICC Profiles

Although some manufacturers charge for profile downloads, most fine art paper manufacturers make them freely available on their websites. Once you’ve downloaded a profile for the paper you plan to use, it’s relatively simple to install it and most profile suppliers provide details with downloads. It’s easiest to download new profiles to your desktop and then move them into the Color directory of your System file (it may be located in the Drivers folder). You will need to restart the computer to install the new profiles.

Most suppliers of fine art papers provide downloadable ICC profiles for a range of inkjet printers.

To print your images using the ICC profile data you have saved, click on File>Print then check Document Adobe RGB (1998) for the Source Space and select the chosen paper Profile from the drop-down menu in your software application. Note: you may need to use the Print with Preview option to access these settings. The Intent should be set to Relative Colorimetric or Perceptual.

Follow the directions given in Using Printer Drivers and Editing Software for setting up the paper size and orientation and select the printer to open the printer driver. Select the paper you wish print on from the drop-down menu provided (or the type that most closely corresponds to the downloaded paper profile). Ensure your printer is set to the highest output resolution and for Photo quality printout, favouring quality over speed.

If a Color Management (or ICM) dialog box is presented, check No Color Adjustment. If a Smooth Edge box is presented, ensure it is checked. Save these settings for future use. Select Print with Preview and check that the print is arranged on the paper to your satisfaction. Then click on the Print button.

Unprintable Images

Printed images usually look much ‘flatter’ than images viewed on-screen.

Consequently, some images that look great on your monitor may not look as good when printed as they do on your monitor because of the differences in dynamic range between images viewed on a backlit screen and output on paper. The higher the dynamic range, the better the media will be able to reproduce wide differences in scene brightness.

Although a good monitor can have a dynamic range in excess of 15,000:1, the dynamic range of photographic prints tops out at 100:1 and, in that range, the normal human eye can only distinguish between 100 and 200 distinct luminance levels. In addition, certain highly-saturated colours are beyond the capabilities of current inks.

The Importance of ICC Profiles

The International Colour Consortium (www.color.org) was established in 1993 to create, promote and standardise an open, vendor-neutral, cross-platform colour management system structure, based on device and media profiling. ICC profiles offer the only scientific method of achieving colour consistency across different devices. However, you need profiles for each step in the colour workflow.

ICC profiles are a critical element in colour management because they allow you to reproduce colours accurately across different platforms, applications and devices. They are also device and media specific. For example, the ICC profile for a printer is based on the printer engine, the paper, the ink and the resolution; change any one of these parameters and a new profile will be required.

Printer profiles help you achieve the best reproduction your output device allows because the image data you send to the printer allows the printer driver to match the requirements of the paper type you have selected and the output dots/inch (dpi) used to make the print. Output dpi is set by the printer’s driver, either as an actual figure (as in more sophisticated photo printers) or implicitly by selecting the ‘Photo’ or ‘Best Photo’ mode.

Most capable software applications now come with built-in colour management systems that can pick up the relevant profiles from the device drivers and apply them – with a little assistance from you! This usually means selecting the correct paper type in the printer driver.

Soft Proofing

Users of recent versions of Photoshop can take advantage of a handy simulation function, known as Soft Proofing, to see how an image will look when it’s printed out on a particular paper. This facility does not change the characteristics of the image; only the preview. It can be used for any printer and paper combination where a profile is stored in your system – but not for non-profiled set-ups.

The soft-proofing process makes your monitor display its closest analogue of what the actual print will look like. With an accurate printer profile and correctly calibrated monitor a soft proof lets you see how an image will be affected by the colour performance of your printer and fine-tune it before you print. You can also try different rendering intents and different proofing colours and create a version of your image for printing on a specific printer. In this way you are able to obtain the best possible reproduction of the image on each printer you print it on.

Step-by-Step Soft Proofing

Step 1: Open the image file and select Image>Duplicate to copy it. Arrange both copies so you can easily compare them (side-by-side or one above the other).

Step 2: Select View>Proof Setup>Custom and from the Profile dropdown menu, select the printer and media type you are using. Set the Intent to Perceptual. Note: Intent settings allow you to control the way the colour management system in your PC renders image colours for printing. Perceptual maintains the relative colour values among the captured pixels as they are mapped to the printer gamut, while Relative Colorimetric maps the white point in the image to that of the destination profile then adjusts all other colours so they retain their relative positions to that point. Colours that fall outside the printer’s gamut are clipped. Perceptual is the best option for most colour printing. Relative Colorimetric may work better with a printer that can produce all the colours in the image or if the image’s colour gamut is limited.

If you want to see how the image is likely to look when printed on the selected paper, click on Simulate>Paper White. To see the effect this control has, look away then uncheck Paper White and look back. Check it again and click OK. (Note: checking Black Point Compression will create a solid black when any black areas are printed out. It is suitable for a very limited number of paper profiles.)

Step 3: Press Control + Y (Command + Y on Mac) to view the Soft Proof. The image should change to show you how it will look when printed on the selected paper type.

Step 4: Save any changes you have made by tagging the filename with ‘for inkjet’.

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