image darker on one portion of the plate

[jithu.sreekuttan]

sir we have been facing a problem recently that one of our press customer is saying that in there plate a half of the portion on the plate the plate seems darker than the other portion
but we have so many customer with the same plate size but they haven't reported any complaint and not only that we have so many customers with different plate sizes they also dont have any problem .
If it would be a problem related to laser or pre-heat other customer would have been complainted,so sir i want to know what may be the possible chance ofor this cause in press,if in pre-press also i need ur kind advice and response

 

[Lukas Engqvist]

You should be able to test it on the plate. You can either set control strips across the plate and measure to make sure that plate is consistent, or try to rotate the image area 180° and that way be able to verify that the plate is correct. If the plate is not correct then there would be needed more data on the setup. If the plate is verified to be stable then the press is having trouble. Is ink and dampening consistent? (run a full sheet 30% each CMYK to see how it prints. Gradual toning or blotchy?) Has the printer changed anything recently…*again one needs more information of the setup, a press technician should be able to analyse what he sees, but guess is there is some ink feed or roller that needs adjustment to be parallel.

You need to break your problem into smaller pieces and eliminate problems by verifying that steps are ok one step at a time.

 

[BeauchampT]

I agree. Unless the printer has some solid data to back up his claim....

A good question for them would be to find out how they figured it was the plate. It might be that they just don't have the best equipment for evaluating the problem.

 

[arkay_desai]

Lukas is right, set color strips all 4 sides and take test plates, take 30 or 50% screen on entire plate and check. Best equipment as I am using is IC-PlateRight. You can ask to customer for test print with test plates if every thinks are correct @ ur end.

 

[sveibl]

Are they Baked Plates?

Are they Baked Plates?

I have experienced this with baked plates. Oven temp inconsistant and made emulsion appear in different shades. It looked odd but did not effect ink pick up on plates.

 

[jithu.sreekuttan]

image darker

image darker

thank u for all of u who have given me ur kind advice .i got cleared the problem .any way i need ur help and advice further .
so wish u a very good day for all of u.