colour variations?

[printmaster]

Hello everyone,

We have recently encountered problems when tiling a job.
Basically when joining the printed sheets we see unacceptable
colour variations, so much that it is impossible to deliver the job to the client.
Any suggestions or recommendations?

We use:
Roland VS-640
Oracal vinyl
Versaworks latest updated edition
Marabu Inks

in a temperature controlled environment

Thanks in advance !

 

[bob]

What software? Are you letting the software do the paneling?

If the latter you might want to manually set up your panels. If possible selecting panel breaks in areas of low contrast or, sometimes even better, actually doing a contour cut at a point where there's a dramatic shift in color if possible.

There's no rule that panels have to be rectangular. Say, for example, if you had an image of a dark mountain range against a light sky. Make a panel break at that point and make the overlap sufficiently large that it spans the lowest to the highest mountain. The just manually cut the mountains off of the sky on the top panel.

 

[printmaster]

I have tried tiling in Versaworks and "pre"-tiling in illustrator but still have the issue.
I suppose I could try what you suggest, but I would still like to find the problem and solve it if possible.

 

[Rooster]

Check to see if they match when printed at a slower speed setting. It's not uncommon for piezo heads to suffer from ink starvation at faster settings. This could be what's affecting your color reproduction.

 

[Bill43mx]

I've seen this suggested before...don't know that it will solve your problem but it might be worth a try. Alternate the orientation of your panels so that every other panel is printed upside down. If you run everything straight through the printer then you are matching up the left side of one print (as it came out of the printer) with the right side of the next. If every other panel is filpped before printing then when you install the panels the adjacent edges came from the same side of the printer.

 

[marcsitkin]

Printing in uni-directional mode and flipping panels 180° when printing should help. That way adjacent left edges and right edges are on the same side of the printer.

 

[printmaster]

Thank you all for your suggestions, we are currently doing some tests !

 

[Mike Paul]

Another thing to keep in mind is to try to have enough laminate for the entire run.
I once switched Oracal 290 with another roll of Oracal 290 after running out and it gave me a slight color shift between panels.
Different lot# most likely the problem.

 

[printmaster]

tried uni-directional printing and flipping the tiles accordingly, and now have less colour variation between the tiles, but a big difference between the uni and bi directional printing. and printing 250 - 300 meters unidirectional is not reasonable.
still waiting for a response from the Roland dealer !