HP z3100 as colour proof printer

[noob]

I have a HP z3100ps printer which I use as a colour proofer. Its a self caliberation device (built in X-rite spectrometer).

Now the business cards I have sent out to be printed via offset have come out totally different to the digital proof via the Hp z3100. CMYK values are: 92,84,0,0. The inkjet print is dark blue. The offset prints are purplish blue.

The Offset printer says its the artwork and their presses are printing the colours correctly. The printer says inkjet proofs will not match their presses because of the way it lays down ink (inkjet v offset press).

Is this total bullshit or is there something I need to know about colour proofing via inkjet for offset presses?

 

[Mike Strickler]

Re: HP z3100 as colour proof printer

Good question. No, not complete bullshit. The color could be anything from a dark blue to a purplish blue, depending on what you mean by these terms, the car stock, press type, and many other factors, such as wet trapping, etc.. Most people don't realize that ink percentages don't describe color unambiguously. If you want to be precise specify a Pantone color or an L* a* b* value, not ink percentages. If you want to have a valid proof, you need more than a good printer. Your proofing system must be set up to simulate the specific printing conditions under which your cards will be printed. This is not quite so simple as you might think, even with a good printer and RIP, such as the Z3100 PS. To be accurate it would have to have and convert from an ICC reference profile that accurately characterizes the press/substrate system, must itself be correctly profiled, and have some means to verify that your proof is matches the reference color.

Please feel free to contact me for further information.

Mike Strickler
MSP Graphic Services: Prepress and Color Management
707.664.1628

 

[WharfRat]

I would agree with Mike
Without Destination profiles and source profiles
your are guessing at your color
Your HP is only calibrating itself with the built in spectro
not profiling itself with specific papers
and
without destination profiles - even just gloss and text -
there is nothing to shoot for
Just off the top of my head
I would say
92-84-0-0 = purple
which is confirmed with my software and proofer
To get a nice Dark Blue you would need somewhat less Magenta
and a whole lot of Black
Like
100-65-0-70

MSD

 

[noob]

Thanks for the responses guys. Time for more reading I guess.

I have only printed photos on inkjets and have only needed properly caliberated monitors and printers to get accurate colour. Offset is at total different animal.

 

[Rodi]

Cyan ink, its weak, it always needs to have more than the other colors to keep neutrality… Having a good amount of K will keep the blues consistent too.

You should have gotten a physical proof, it is worth the extra money to insure you will get printed what you want.