[cairo] Spot colors (and CMYK)

[ecir hana]

On Sat, Feb 20, 2010 at 12:35 PM, M Joonas Pihlaja
<jpihlaja at cc.helsinki.fi> wrote:
>
> Why not?  I don't expect cairo to ever be able to render with spots
> which it can't understand simply because the vector backends fall back
> to the raster backend for some operations.  I think that expecting
> cairo to be able to use some random spot it knows absolutely nothing
> about is expecting too much.

Because of two things: making ICC profiles mandatory would make you
unable to use spots you don't have profile for, such as Pantones. A
spot is just a name which doesn't even need to have LAB alternative.
Second, no matter where I print or what profile they use I want my
text to be CMYK(0, 0, 0, 100).

That said, I understand that untagged CMYK is difficult to show on the
screen. I'm not against tagged content - I'm against making tagging
mandatory for spots. Perhaps always tagged CMYK is even a good thing
but for DeviceN that means only its fallback. (And I could always
create untagged DeviceN with cyan, magenta, yellow and black). I also
believe DeviceN should have its fallback defined in CMYK only, and the
fallback should compose over CMYK only, as well).

Btw. it's not about vector falling back to raster - it's more about
different color spaces.