Digital BW, The Print

Garry,

You wrote:

>I would like to have my sepia more yellow than Pauls example on his
>site. Is the colour changable with the curves or is it purely
>saturation of that premixed tone.

The color of the toner is fixed.  The curves vary how much goes into the
print, but not the tone of the toner.  So, you'd have to mix you own to get
more yellow.  This might be fairly easy, however.

>I have tried full colour MIS pigs to achieve my particular flavour
>of (goldern) sepia and achieved good results, especially with
>antique white (cream) paper, which reduced the cross over look as
>the tones went from warm ink in the shadows and mids to un-inked
>white sections of paper.

If you have MIS color pigs in you machine, print a purge pattern on your
paper of choice and save it as a reference.  Then, if you have any of the
MIS VM system inks, print a purge patter with them and see how the g/s
visual density  of the pure yellow compares to the density of the toner.
It's possible that it is close enough that just adding some yellow to the
toner (yellow cut 1:1 with MIS quad 25 for the photo/light toner) could be
all that needs to be done.

The current sepia toner uses ratio of 2Y:1M for half it's volume.  The other
half is a mix of clear base and MIS 25 to control the density and cut the
gamut.  (I want the lightest, lowest gamut toner that is consistent with
achieving the tones I like in the final print -- the less color ink the
better.)  The density of the toner must end up fairly close to the MIS VM
toner for the existing curves to work right.

Good luck.  Let me know how it goes.

Paul
http://www.PaulRoark.com