We have a Vutek QS3220 and we are printing color + white ink on a 60 clear PET window film.

We previously ran these with no problem, but all of sudden are encountering what looks like a "suction / print line" about every 10. Since then, we have printed on canvas, regular adhesive back vinyl, and even 3/16" clear acrylic - all prints came out fine so we believe the issue lies with the suction since the PET film is so thin.

We have tried the following,

• Printing on both left and right side of the flatbed
• Reducing the heat / vacuum levels
• Hooking the film onto both tension rolls (Previously when the prints came out correct,  we had 100% suction they were not hooked on the tension lines, it was fed by a table roller)