yellow

have to print yellow in first unit due to ink getting filthy. any dark solids, process etc, previous to 4th unit. water, room, board temp and types of ink change do not seem to have an effect on what is happening. any help? (ls40)

 

try adding about 20% transparent white or varnish to the yellow. This will weaken the yellow ink requiring you to run your ink sweep up a bit. The thicker ink film will be less likely to get dirty from the colors down before it. Be sure to also run all your color bars up to full density even in zones that have no image in line with it.

 

ta very much but have already tried this. def weird. could be board or most likely crappy inks. i dont buy the materials in but if its cheap your expected to get the same results in the end!!

 

Sorry haven't been on in a while and may be too late but have you tried tack reducer in yellow ink? advising you to run good weights is also good advice, as the tack increases as your ink film gets thinner. think of the principal of glue ie a thin film has more tack and pull than a thicker film of glue. Good blankets and ink/font balance is also important. I hear what you say about the consumables changing all the time and its normally when you're in a good place on press too that management change suppliers of one or more things!! grrrrr! they don't seem to give any respect to the process at all. Tinker tinker bloody tinker. sometimes cheaper is definately more expensive! hang in there!

 

we used quick release blankets a bit harder than normal but this worked