Originally Posted by
Kev Williams
I'm thinking this is a form of 'banding' that nearly all lasers suffer from...
Ray Scott posted up awhile back about mis-matching resolution settings, such as, if you're engraving a 300dpi bitmap, you should set the machine's resolution settings, particularly the Y axis, to match the bitmap. I'm assuming multiples work, such as 400dpi Y is ok with a 200dpi bitmap... Every C02 laser I've owned has done the half-good then half-crappy engraving. Since I read Ray's post and kept that in mind, I've haven't seen the problem.
The problem with this advice as applied to RF/metal/ceramic lasers, is that many of these, like Trotec, have fully automatic settings for creating halftone engraving, and who knows what settings are used? They should match the user's output settings.
I don't know what settings you're using, but try this: paint that skull graphic GREEN. Doesn't matter if RGB or CYMK. Just paint it green. Then, not using any special settings, engrave it in 'photo mode' as if it was a photo- this means your engraving settings must be done with the BLACK color. Use whatever power and speed you were using, set the resolutions to 300 dpi both directions. Or 400, shouldn't really matter... leather is forgiving and doesn't usually need higher res unless doing tiny work...
What should happen is the program will create a dithered halftone output that will 'bust up' the laser beam's output continuously, and with luck, will prevent those lines--