ICC Profiles, What Are They?

Article written by:  John Citizen, Desktop Sign Systems, August 2000
This is a posting done by John in response to a thread on the Delphi forum re-published here with permission of the poster.

Creating ICC profiles for dye sublimation (and other substrates) is something I have to do nearly every day. I will try to explain the theory behind ICC profiles and why the statements like 'our ink just print the correct color' is nothing more than a sales ploy. Warning... quite a long post! 

A program that uses ICC profiles should let you print predictable colors without color replacement. However this is not ALWAYS the case, especially when a particular spot color is involved. But you need a different ICC profile for every combination of ink, printer, substrate and resolution. 

The same ink printed at different resolutions gives you different color. If you print an image at 720 dpi, and then print the same image at 360 dpi you will get different colors. Different amount of ink is put down (saturation of color) depending on what resolution you use. So therefore you need a different ICC profile for 720 and 360 dpi.  The same ink printed in different printers gives you different colors. Different printers but different amount of color down as well. Even at the same resolution, things like nozzle size and the like affect the amount of ink that goes down. 

The same ink transferred onto different substrates gives you different colors. I can do two exact prints with the same ink onto the same transfer paper. I can transfer them to two different substrates (both recommended for sublimation) and I will get different colors depending on the chemical make up of the substrate. 

My point is the key to accurate color is not reliant on JUST the ink. It is reliant on the solution of ink + substrate + transfer paper + resolution + printer. The ink is only a small component of the total solution. 

For accurate reproduction there are two things. First is that you must have a solution capable of printing the color, you can not print a color if your ink is not bright enough to reproduce it. Second is that you the software has to be good enough to take advantage of the color. This is where ICC profiles are supposed to come in. 

We sell a variety of software packages and we find that some will print more accurately then others. A lot more is dependent on the software, not just the ink. This is because the software is responsible for tying all the components together, ink, paper, substrate, etc... to reproduce accurate color. 

As far as color correction goes you still have to create an ICC profile for each different substrate you print on. So yes there is color correction involved to that point. Although you should only ever have to do this once. Not at every print. 

There are some other issues as well, but I don't want to drown anybody more than what I already have. 

John Citizen 
Desktop Sign Systems 
www.dtss.com.au 

The above review is: Copyright 2000, John Citizen, Desktop Sign Systems , All rights reserved, and may not be copied or reproduced without the written permission of the author.