Control halftone density (screen density) on C75

[Joe Arseneau]

Have you tried setting Indesign to not control the color? Your last screenshot shows that Indesign is determining color, so a lot of things applied at the Fiery will not work correctly.

Also, you are missing the Printers profile in Indesign, so again, all settings will be outputting generic code and not optimized.

If using Command Workstation 5:
Select “Device Center”
Resources
Profiles
Output Profiles
Select All of them and click “export”
Choose where to save them (in my case a flash drive)
OK

At the PC with Indesign: (Done on Win7)
Browse to where you saved the files above.
Right click on each of them and choose “Install Profile”

In Indesign (CS3 and CS5 in my case)
Click “edit”
Assign Profiles
In CMYK section
Choose the Fiery Xerox C75 and closest paper
OK

[AllenPrinting]

I'm tyring to make a plate for an offset press by printing it on a C75, and my plate has gray on it. When you print in black onto the plate, that gray is simulated as a screen (obviously). My problem is this: The default screen density that the C75 outputs on the plate is way too fine for the ole press to reproduce. When you put that plate on the press, the screen just mushes into one blob.

The first thing I tried was to go into command workstation and change the "Printer screen mode" to 150 dots. For the plate job. That appears to have some positive effect on loosening up the screen, but it's not enough.

The second thing I tried is using Indesign print dialogue. In Indesign I set my output mode to separations, then selected the black ink (the only one present in the document) and set it's screen density (lpi) to a really low value (5 or something ridiculous like that) to see if it would have any effect. No luck. It seems that whatever indesign is sending to the fiery is being overridden by the Fiery RIP when the file is processed.

Third, I tired to stop the Fiery from doing any profile conversion or graphics handling (hoping that I could stop it from over writing what Indesign was giving it). This is guesswork on my part, but I went into the basic color settings and input the settings seen below:

That didn't work either.

Fourth, I tried sending the file to the hold from indesign as a simulated proof with a different destination profile. I'm guessing again at this point, but my rationale is that a profile such as newsprint will maybe have coarser screens (i'm not really even sure if the profile has an affect on screen density). This was again done with composite gray selected in the output tab and screen frequency set to 5lpi. Once again I cloned my command workstation color settings from above. Settings below:

So what gives? What combination of settings do I have to use to get the Xerox / Fiery to relinquish control of the screen density and let me specify it out of Indesign. I'm sure there's a lot i'm missing here so i'm hoping someone with a fuller understanding of the processing flow will be able to enlighten me.

P.S. I did discover pretty early that if you purchase the EFI Graphic Arts package, it will allow you to simulate halftones on your job, but unfortunately it costs $7000 to purchase new. I'd really rather not resort to that if at all possible.