Printing Digital Photos

At the heart of all colour management is a system of ICC profiles. These data sets contain information that characterises a colour input or output device in accordance with standards set up by the International Colour Consortium (ICC). Each ICC profile describes the colour attributes of a particular device by defining the most saturated colours the device can produce in a standard colour space.

 
The International Color Consortium provides standardised support for the colour profiles that are used in every colour-managed workflow.

The system works by enabling device users to compare the colour reproduction of each device against the known ICC standard. Any variations from the standard are recorded in an ICC profile, which is used when one device is connected with another. By having a standardised reference, colour reproduction can be controlled throughout an entire imaging chain or 'workflow'.

An ICC profile can be created for every device or medium that captures or displays colour. The ICC specification covers colour devices in three broad classes: input devices, display devices and output devices. Input devices include scanners and cameras; display devices include monitors and projectors, while output devices include papers and other printing media.

To profile a device you must map the way it reacts to a standard colour input using a device known as a colorimeter, which analyses the three components of each colour: hue (colour), saturation (intensity) and lightness. Once this information is known, the device can interact with other profiled devices to ensure the result of the interaction is as close a match to the known standard as possible.

An important component in the colour management system is the profile connection space (PCS), which is defined by the ICC as a way to link the profile of the input with that of the output device. In the PCS, the input profile and output profile interact within a colour management engine (CMM) that ensures consistently accurate and repeatable colour reproduction across a wide range of output devices and media. Consequently, if two colours have the same colorimetric measurements they should be identical when viewed under standardised viewing conditions, regardless of the device the profiles came from. 

Profiling in Practice
The first step in building a profile for a device or printing medium involves measuring a set of colours from the device or paper. This should be done under tightly controlled conditions because viewing conditions can influence both the measurement device and the measurer's reactions. However, unless you are a serious enthusiast or professional photographer, it is probably only worthwhile doing this if you plan to make enlargements for display or exhibition.

To simplify printing for everyday photographers, most printers - and all high-quality photo printing papers - come with pre-set ICC profiles. These 'canned' profiles provide an excellent starting point and are usually highly effective and very convenient to use. They are normally included in the printer driver. Most will interact with editing software, allowing you to select the correct profile in your image editor and communicate it to your printer.

When you use the printer manufacturer's profiles, they should appear in the Media Type dropdown menu in the printer driver.

'Canned' profiles for the printer manufacturer's papers are pre-loaded in the printer driver.

 
All profiles that have been loaded in your computer - including those from the manufacturers of all printers you use - should be selectable in your editing software.

Custom and Stock Profiles
Serious photo enthusiasts may wish to follow in the steps of most professional photographers and photo printers and create individual profiles for their own printing set-ups. The reason for doing this is to guarantee that what is seen on the computer monitor is reflected accurately in the printed output.

This can be a huge time-saver for anybody who makes large volumes of prints and photographers who may receive orders for reprints months - or even years - after pictures were taken. For anybody who only makes a few copies of prints (even if they must be of exhibition quality) and those for whom time does not represent money, the canned profiles supplied with printers or profiles created by manufacturers of fine art papers will usually be close enough to require little or no further adjustment.

Photographers who wish to work with Custom profiles must be prepared to profile every device in their digital workflow: monitor, printer and papers and use a standardized viewing device for evaluating prints. Some paper distributors offer this service and it's usually too costly for enthusiast photographers.

Stock profiles are available free of charge from most paper distributors. They are specific to different paper/printer combinations and can be useful if you want to use papers that come from a different manufacturer from your printer. Manufacturers of fine art and high-quality printing media usually provide downloadable profiles on their websites. The section 'Using Third Party Profiles' below shows you how to locate, download and apply profiles for third-party media.

Why Profiles Are Necessary
Accurate profiles are the key to a colour-managed workflow. If you don't have a profile you can't specify a precise hue value for any colour. For example, you may be able to say something is green; but you can't say precisely which shade of green - or whether the green is light or dark. Furthermore, you can't be sure the green that is printed is the same as the green you see on a computer screen.

If your monitor and printer profiles are accurate - and you are using profiled printing paper - the prints you make should closely match the images you see on your computer monitor. This can be a significant time-saver as well as saving you valuable paper and inks.

By presenting you with an accurate representation of the colours and brightness levels of the image, you will be able to ensure the majority of your prints are correct from the start (although we still recommend producing test strips, a strategy that will be outlined in Test Strips and Proofing Options, to minimise the chances that the image will not print out quite as you expected).

When you print without ICC profiles you have to make a series of test prints and progressively fine-tune the computer settings until the colours and tonal range in the print were correct. Even if your monitor and printer are profiled, printing on non-profiled paper is risky because you can't be sure the paper's colour gamut (range of colours) will match the colour gamut of your image editor - or the printer.

It's tempting to try manually 'tweaking' driver settings to get better colour by process of elimination but, although this may improve colour reproduction, it can't guarantee colour consistency from print to print or accuracy across a wide range of colours. You can waste a lot of paper - and ink - trying to sort these problems out. Use of ICC profiles is the only way to ensure accurate printed colour for all colours a printer can reproduce

Be wary of using papers that come without profiles as it may take time to determine their printing characteristics.  And be especially wary of papers that are branded as 'suitable for all inkjets'.