I have a shiney new 1390 x 130w chinese laser and have been working on learning the sofeware (lasercut 6.1) and the control panel and the machine for a couple weeks (weekends and slow times during the week). I am getting cutting different materials pretty well, I think... so this weekend was time to do some vector engraving. I am using Romark and Duet (Gemini) .060 plastic- mostly brushed silver and gold and taking off the liner and masking with transfer (premask) take. I am getting the engraving to work fine, but the burned out plastic has what I think is a coating of the adhesive from the premask tape- which looks bad and does not clean off very well. What am I doing wrong? Thanks Gene