colour profile
A colour profile is a small file that says what a colour actually looks like, so that the same numbers give the same colour on another machine.
What the word means
A colour in a document is a handful of numbers. On their own those numbers mean nothing. The same three of them give one red on your screen, another on a telephone, and a third on a press.
A profile is the missing sentence: on this device, these numbers look like this. Attach it, and any program can work out what to do to get the same colour out of another device. Without it, everybody guesses, and the guesses differ.
What it does on a real document
A document going to print states its colours in ink and names the profile of the press those inks were chosen against. The printing works reads the name and knows what the numbers are meant to look like.
On a document kept for the long term the profile is not merely named: the whole of it is copied inside the file, so it cannot go missing later. The engine also writes such a file on its own, so a reader can see what one is made of.
Where it comes from, and why
Eight companies set up the International Color Consortium in 1993, because each of them had its own way of describing colour and nothing travelled between their programs. What they agreed on that year is the profile that still carries their initials.
The form is published as an international standard, and it is still the one in use. Two versions of it live side by side, the second and the fourth, and a program that reads one usually reads the other.
See it on a finished document
The embedded ICC profile The same numbers, said so they mean something The rules behind this word, and the texts they are read from
Glossary
- CMYK
- The four inks a printing press lays down: cyan, magenta, yellow and black. A screen mixes light instead, so a document going to a press states its colours in inks, not in screen colours.