Re: Profiling with Rhodamine Red
Re: Profiling with Rhodamine Red
- Subject: Re: Profiling with Rhodamine Red
- From: email@hidden
- Date: Tue, 1 Jul 2003 11:31:27 -0400
colorsync-users-request@list
s.apple.com To: email@hidden
Sent by: cc:
colorsync-users-admin@lists. Subject: Profiling with Rhodamine Red
apple.com
06/28/03 10:00 PM MST
Please respond to
colorsync-users
Lee,
The use of rhodamine red in place of magenta used to be a common practice
years ago in the production of horticultural catalogs. But in those days
there was not much in the way of process control in practice. Pressmen were
considered artisans, and press proofs reigned supreme (Cromalin was in its
infancy and was the only useful photo-mechanical proof on the market). I
have not heard of this being done in recent years.
To do this today and have good process control would take a great deal of
work, printing IT8 targets, profiling, etc., and would be very expensive.
Are you sure the colors you need are outside the gamut of Toyo CMYK? Also,
I believe they do make several sets of cmyk inks with different chromas,
but then you are getting back into profiling a system.
If it were mostly saturated colors, you could try making 5 color seps using
rhodamine as the 5th color. Same problem proofing but you have much more
latitude on press. Your color technician would have to do some work to
figure out how to modify the magenta channel to reduce the magenta in the
colors you are going to hit with rhodamine, but it is not too hard to do.
Use the magenta screen angle for the rhodamine too. It has been quite a
while since I have been involved in something like this but I think you
probably want a maximum of 20-40% rhodamine in the areas of concern with
about the same amount of reduction in the magenta in those areas. You must
print on at least a 5 color press (this may seem obvious but I mention it
so you don't try a second pass to add the rhodamine) and since there is
nothing else on the "kiss" plate you have much control on press to adjust
its density. The whole thing is much more forgiving than you would think.
But nothing would be less costly than getting the standard inkset to
produce the color you want.
Lastly, the CMYK gammut on a press is pretty limited. Many colors fall
outside of it, especially if you are converting spot colors or trying to
match a logo color that was not chosen with the cmyk gammut limits in mind.
The best available compromise is often something we have to live with.
Good luck.
Mark Muse
>
I have a problem with a job that is being printed with Toyo inks.
The color of the Toyo magenta is making a clean pink impossible.
It's also killing oranges.
The toyo magenta is very "purple." That is it has a lot of cyan in it.
So what I'm going to propose is substituting Rhodamine instead of the
Toyo magenta.
Anyone ever try this and what should I expect for the results?
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