KM C7000 Color issues

[Erniek]

Does anyone with a C7000 have any recurring color banding issues? We have a 6500 as well and it has the banding problem but after 5years we have been able to work with it acceptably. But with the 7000 we were told that the banding problems were not an issue any longer but in practice this has not been the case with our machine since we had it installed in July. We have had 3 different escalations with KM and at the last one they said the machine was in spec. They are telling us from the service side that this issue has always been in play to some degree and it is part of the design. We really like the KM machines but with the 7000 we are quite disappointed with the output. Anybody have any input about this issue?

 

[Emtri]

What sort of banding? Large light solids? is it all stocks or just certain ones text/cover? At least on the 6500's there was a few adjustments you could play with to help minimize this, But I have no experience on the 7000

 

[Rikkie]

If the banding is in the direction of travel, you're probably looking at dirty / damaged coronas. If perpendicular to direction of travel, you need to look at the transfer belts. Very thick stock can also cause this, but clearance between stock and transfer belt can be adjusted to correct this. Our 6500's handle solids / screens / vignettes very nicely with no banding, regardless of coating. It CAN be fixed. Maybe you need to look your supplier in the eye....

 

[richsweeney]

banding

banding

If the banding is in the direction of travel, you're probably looking at dirty / damaged coronas. If perpendicular to direction of travel, you need to look at the transfer belts. Very thick stock can also cause this, but clearance between stock and transfer belt can be adjusted to correct this. Our 6500's handle solids / screens / vignettes very nicely with no banding, regardless of coating. It CAN be fixed. Maybe you need to look your supplier in the eye....

Have you tried various output settings from acrobat?

 

[Erniek]

Have you tried various output settings from acrobat?

Would acrobat settings cause banding issues?

 

[printsnpaints]

When you use too shallow bit depth (i.e. 8 bits/channel) for tensive image processing or for processing wide gamut colour spaces banding may appear, in particular in the shadows.

 

[buckeye]

Pictures are worth a thousand words, can you upload an example? Are you able to change line screens such as Dot 1, Dot 2, Line 1, Line 2 or Stochastic on the C7000? If so, this could possibly help if you're referring to the banding that goes on in vignettes for instance.

Erik

 

[Toner4Brains]

If the banding you're referring to occurs cross-wise on heavy stock, turn on Thick BK Mode when you are running that weight paper. It is in User Setting > Common Setting. If that doesn't fix it PM me with more details on the banding.