Mailing Lists: Apple Mailing Lists
Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Inkjet Proofer Separation Parameters

In a message dated 5/28/02 1:34:58 PM, email@hidden writes:

I am profiling a commercial printer's HP5000PS inkjet proofer, which
they have carefully calibrated to their presses. I'm using
ProfileMaker 3.1.5. When setting the Separation Parameters for the
profile, should I use the numbers I got from the prepress manager
(UCR,Total Ink 310%, Maximum Black 98%, and Black Start ?) or
should I use one of the canned Inkjet Separation Parameter sets in
ProfileMaker?

You need to distinguish between the ink settings and black generation for the
press, and those for the inkjet. There is no direct relation between them,
except that one will related to the other when proofing the press on the
inkjet. Choose inkjet-based settings that work well on that particular
inkjet, with those inks, on that media. Be sure that all the color
adjustments in the internal RIP are shut off before printing the target...
this usually takes me about three tries for the 5000.

This printer is using a Heidelberg CTP system which included the HP5000PS as a proofing device. The exact Heidelberg package I can get later this morning. I think they told me they use PrintOpen to keep the inkjet calibrated to the press. (Most likely I should provide them CMYK files that are "untagged.") I'm assuming that the inkjet is "tight" with the press, and maintained consistently in that state.

The numbers stated above are for the press. Based on some recent experience with completely different shop that uses an Imation CTP and a HP5000PS, I tried the following:

From the same test chart readings profiles were generated with three different sets of separation parameters (one set based on their press, and the two canned sets designed for "stand alone" inkjets provided in ProfileMaker). Test prints from these three profiles were all quite acceptable. All three were almost identical in color, but the blacks were different. Because of the expense, the shop would not make plates from these files and run them on the press to really ascertain their quality. So, my main concern is, which separation settings will produce the best plates? In the case of the shop with the Imation system, the press separation parameters profile produced an inkjet proof that had weaker blacks than the proof produced with the profile that incorporated the canned inkjet settings. The prepress manager there suggested I use the profile with the weaker blacks to give the pressman some wiggle room. (This would be fine assuming one can always be there for a press check.) The profile with the canned inkjet separation parameters looked richer overall, and one would want that "look" in the final printed piece, but the fear of producing unmanageable plates has driven me to ask these questions on the list.


--
Jack Kelly Clark
Principal Photographer
ANR Communication Services
University of California
Davis, CA 95616
(530) 757-8987
http://anrcatalog.ucdavis.edu
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.
References: 
 >Re: Inkjet Proofer Separation Parameters (From: email@hidden)



Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.