Problem printing black screens on Xerox 250 with Spire RIP

[pworden]

Black screens print with visible outlining around objects, and the screening overall looks scuffed. I've tried all the obvious thinks such as changing drums, fusers, paper, humidity; also tried various settings in the Spire changing screening, quality, overprints, all with no solution. I've bypassed our workflow and sent PDFX1a and even PostScript to the Spire - all previews look good and clean, but the screened black areas continue to look outlined and scuffed. If I swap the black for just cyan, for instance, and send that file to the Xerox - the screened areas print well - it's just the black. Xerox has been trying to solve this for a few months without any progress. Has anyone else had this problem?

[DigiCorn]

In the Fiery, have you tried setting "black detection" and "black overprint" both to OFF? It's also possible that the black could be out of registration. Without calling out a tech, you can open all the doors, pull out all the drawers and flip all the switch handles to an open position. Then, close them back up. This "resets" the machine (because it thinks maintenance has been done), and might readjust the registration. Also, when was the last time you calibrated it? One last idea is that the black developer has become contaminated. Have the tech do a developer dump and put in fresh consumables.

[pworden]

No Fiery - a Creo Spire without settings like that. I'll try the reset but doubt it will help since Xerox has been here several times trying different things, and had the machine open of course. They replaced the developer housing and that didn't work. We calibrate a couple of times a week. It doesn't look like misregistration, it's a real outlining a bit darker, around a letter, a shape, whatever uses a black screen. I don't know if the tech dumped developer when they replaced the developer housing... I'll ask.  Thanks.

[David]

Is the RIP doing some sort of trapping, maybe?
Is the issue with just tints of black or with solids as well?
All tints or just certain %'s (like a screen of 50% or less?)

[pworden]

All trapping is off except that PostScripts overprints from the file source are honored (I've turned this off just for testing and it made no difference). Just tints of blacks but all tints exhibit the problem.

[pworden]

I've attached some iPhone shots just FYI.

File "Example 1 Bad Screen2.jpg" shows the outlining on the gray letters and the gray box - both just use black screens. You can see the outlining and scuffing.

File "Example 1 Replacement Screen2.jpg" shows those same areas replaced with a screen of just CMY. You can see no more outlining or scuffing.

File "Example 2 Bad Screen.jpg" is another shot of the way the black screen looks when printed.

I hope someone has seen this sort of thing before.

[David]

do you have some sort of "anti-alias" turned on?

that is odd looking, it appears to be a "trap", but you say it's not?

[Joe]

It is odd. I've seen it do the opposite where there is a white halo around stuff. Never seen it with a darker line.

[DigiCorn]

Ours does this. It's a Fiery trap/overprint problem. Fiddling with the Fiery eventually you get a combination that looks right. But you're not using a Fiery. Good luck with that!

[pworden]

There is a trap setting in the Creo, but it's turned off and always has been. No trapping is done to the PDF going to it - and of course, it's just the black. Seems like if it was trapping, I would get similar results with, say, a magenta-only screen as opposed to black, but I don't. I know it's weird. Just hoping someone would have an idea. I am waiting to hear from Xerox about dumping the developer and putting in fresh consumables. We have, though, of course replaced the black toner carts several times since this appeared.

[Slappy]

We run a Creo RIP on our Canon 7010 also and I've had some real image quality issues which none of the techs have been able to help with so far. Almost all of them say "Huh, haven't seen this RIP in the field before. Everybody else runs the Fiery." 

I fought with black overprinting & drop shadows looking crappy for a while, but I don't think I've seen that kind of outlining/trapping. Ours is an imagePress CR Server A7000 fwiw. Not sure it's worth digging around in our settings, since I'm not sure you & I even have the same interface but if you have some screenshots of those menus post 'em up and I'll compare best I can.

[pworden]

Here are screen shots of the settings. Note that I've tried every possible selection in all of these windows without a solution. I HAVEN'T tried every combination... but I'm thinking that since it's just the black screens, it would be a waste of time. Thanks for looking them over and let me know if anything stands out!

[pworden]

... and two more.

[David]

have you tried using Absolute instead of perceptual intent?

[pworden]

Yes. Made absolutely no difference :-)
I really think it's the machine. The tech was just here, dumped the black developer, changed the developer housing, still bad. He's chasing up any item that is specific to black. Will arrive with new parts next week.