Re: [Gimp-print-devel] was - P700 and P900 full channel support

[Robert K. <rl...@al...>]

On 11/1/21 1:29 AM, Oliver Kowalke wrote:
> 
>     It should be possible to support this, other than the violet channel.  We could support the violet
>     channel for raw printing (i. e. the user has to do the separations), but actually supporting the
>     violet ink for normal printing would be a fair bit of tuning work and would need to be hands-on.  If
>     you're interested in doing this, be prepared to put a lot of time and a fair bit of consumables
>     into it.
> 
>     The first thing to do would be to look at src/xml/escp2/inks/cmykrb.xml in the Gutenprint source
>     tree to see an example of what we did for the R1800 and R800, which is CMYK+red+blue (which is
>     actually closer to purple, but Epson calls it blue).  The most non-standard part of this is the
>     <Curves> section, which is a set of transfer curves for each ink channel by hue, starting with
>     blue=0.  I always tested these by printing a rainbow sweep pattern and trying to get as good of a
>     match as I could with ordinary CMY(K).
> 
>     My thought about this is that we should at least at first only support the violet ink in raw mode,
>     as effectively a spot color.
> 
> Your description applies to the violett channel?!
> Because I'm new to print driver development I'd like to start with supporting the matte black
> channel. At least I think it should be easier, right?
> What  would be your advice to start?

The channel ID for matte black will probably be the same as it is on every other printer that uses
matte black.