[cairo] Subtractive API, part 0

Chris Murphy lists at colorremedies.com
Tue Feb 2 22:30:22 PST 2010

On Feb 2, 2010, at 7:49 PM, ecir hana wrote:

> On Mon, Feb 1, 2010 at 5:00 PM, Chris Murphy <lists at colorremedies.com> wrote:
>> All of these things have been completely solved, short of actually simulating metallic and
>> fluorescent spot colors with conventional inkjet inks. You can simulate the effect of ink
>> opacity and print sequence. This is done automatically, millions of times a day, all over
>> the world, with CMYK ICC profiles which take all of these things into account. Extending
>> this to spot colors can be done either using deviceN ICC profiles, or proprietary solutions
>> which tend to be more common.
> If all of these things are solved, why is there:
> - just one software which gets it right (Serendipity Blackmagic)
> - need for "iterative proof-correction cycle" to get nice results
> - so many rips, plugins and books dealing with color management
> - a difference between a tagged scanned picture printed on two high-end printers
> - various magentas? (not the paint, but the actual color on paper)

Solved means that it's understood. Solved doesn't mean that every product on the planet completely implements the solution arrived at from such understanding.

And "completely" (solved) is probably going a little too far. Even in Blackmagic, you have to determine the opacity of spot inks, and input this information into the RIP. It doesn't come with opacity information out of the box. But once supplied with the correct information, it will simulate on-screen or on an inkjet the effect of opacity and print sequence.

Chris Murphy
Color Remedies (TM)
New York, NY
Co-author "Real World Color Management, 2nd Ed"

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