Negative Prints using "White" .eps file color coming out screened

preflight

Member
I posted a thread not long ago asking about how to correctly print negatives from Quark Xpress to a postscript file. I got some great responses and realized that there were settings I could change in my Acrobat Distiller to make the negative come out appropriately. Here is the new challenge though:

For some reason, using this process, every time I make my "negative" file, any .eps file that uses "white" does not reverse out properly. It should come out solid black when I make the file into a negative, but it comes out screened. Using "white" from Quark does not do this. Only Illustrator .eps files. I have tried different versions of Illustrator, I have tried .ai files and .eps files. I've tried using Quark, I've tried using InDesign, nothing is working. I've tried changing our printer setting and Acrobat Distiller color Settings.

Here is the process I'm using now (to see if there is something I'm missing). A composite file is made in Quark 6.5 with several different components of art and text. We make a negative postscript file out of that composite (which does not invert completely correctly). Then we take that postscript file, and distill it using Acrobat Distiller (with some settings made so that the postscript file will invert properly as a .pdf) and place that final .pdf in a hot folder for our Colorburst Rip software (printing to an Epson 4800 printer).

The .pdf file views properly. But when it prints, any .eps file that has "white" in it does not turn to solid black, it turns to a screen of it. When I look at the files in Pitstop, the difference is that components that are white in Quark, show a color of "Grayscale brightness 0%". Components that are white in Illustrator are "C=0, M=0, Y=0, K=0". I am able to use Global Change in Pitstop to convert the art to match the Quark components, but I am the only one here that has Pitstop and I'm not the one that makes these composite files. I need to figure out a way for the others here to make them without having to change things in Pitstop. I've tried changing the mode of the white swatch in Illustrator to Grayscale, I've tried saving the Illustrator files as black & white instead of color. Nothing is working.

I know this may seem confusing, but it is really important for me to make this process work for our employees that have to do this daily. Any ideas?
 

esko_pdl

Well-known member
Re: Negative Prints using "White" .eps file color coming out screened

Does this show up only when printing to the Epson? What if you print positive, do you see the "screening" as blueish tint within the white area?
Are you actually dot screening for press to the file before going to the Epson, or is this the screening the Colorburst is doing for the Epson only?
 

preflight

Member
Re: Negative Prints using "White" .eps file color coming out screened

So, this is really weird. I tried printing as a positive instead of a negative and this time, the .eps "white" showed clear (as it should have). But the .eps black showed as a screen of black and not solid. While the black components from Quark printed solid black. So, it's exactly the same issue, just with the opposite color.

As far as dot screens, when printing the original postscript file from Quark, I am using a resolution of 3657 dpi and a frequency of 133 lpi. Print colors are black and white. Is that what you mean?
 

DHarmon08

New member
Re: Negative Prints using "White" .eps file color coming out screened

If I were there at your shop I'm sure I could troubleshoot this problem in minutes, but alas... I am not... =*(

First thing I wanted to ask was is this for 4c process, spot printing, or just straight b/w?

The process we use (if using Quark 6.5 for the layout) is to build the layout the way that you want/need it in quark with the default page background "white" placing graphics into their areas, etc etc then printing from Quark direct to the RIP... IF you HAVE to use pdf.s and the HOT folder... I would suggest printing saving the file as an .eps out of quark then distilling through Acrobat...

First thing I would check if these steps aren't working would be to check the placed graphics individually to make sure that they are all .eps files that have been flattened (have NO layers OR transparencies) BEFORE placed into your Quark Layout...

If the placed elements are the only ones doing the screening effect then there's your problem...

What happens it you output two side by side boxes from quark one set to a 100% black fill and other a pur white fill?

Hopefully I understand your dilema and provided some help otherwise get back to me and I'll try harder to understand... =)~

TTYL

Daniel P. Harmon
Prepress Technician/Platemaker
 
G

Guest

Guest
Re: Negative Prints using "White" .eps file color coming out screened

>First thing I would check if these steps aren't working would be to check the placed graphics individually to make sure that they are all .eps files that have been flattened (have NO layers OR transparencies) BEFORE placed into your Quark Layout..

I don't have a solution or an understanding of preflight's problem, but I find the statement quoted above very odd. My understanding of eps and postscript is that transparency is NOT supported. Has that changed recently?

Al
 

Al Ferrari

Well-known member
Re: Negative Prints using "White" .eps file color coming out screened

>Then we take that postscript file, and distill it using Acrobat Distiller (with some settings made so that the postscript file will invert properly as a .pdf)

Exactly where in Distiller do you set the inversion? Can you describe the settings please?

What you describe sounds like a Rich Black/Rich White sort of conversion, but am just guessing. What are the CMY values in the area that should be 100% black but is not?

What I mean is that it seems the grayscale black is first getting converted to Rich Black before the inversion.

Al.

Edited by: Al Ferrari on Jun 9, 2008 12:14 PM

Edited by: Al Ferrari on Jun 9, 2008 5:17 PM
 

Prepress_Parasite

Well-known member
Re: Negative Prints using "White" .eps file color coming out screened

Sounds like you are printing a black and white composite. Setup your files and print a separation and see what this does.
 

preflight

Member
Re: Negative Prints using "White" .eps file color coming out screened

omg that was it!!!!!!!!! Printing the file color separated to make the negative postscript file worked perfectly. Not only that, the inverting come out correctly so there was no need to distill the file in Acrobat. This is wonderful! Thank you so much!!! Not only did you answer my question, you saved me a step in the process!
 
G

Guest

Guest
Re: Negative Prints using "White" .eps file color coming out screened

I am glad that made it work for preflight, but can someone explain why composite produces the problem?

Al
 

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