I thought I used the manufacturer’s recommended settings for the two engraving layers but upon checking, I didn’t for the top layer. I also didn’t use the manufacturer’s recommended settings for the cut:
Thickness 0.0625 in (= 1/16 in)
Layer 1 (Blue): 1000/15, 675 DPI auto focus
Layer 2 (Black): 650/60, 675 DPI, manual focus 0.06 in
Cut 180/100, auto focus
Note that the Layer 2 engrave settings are to remove the white and blue layers, so you need to do color separations like an old style print job:
With the separations, the laser assembly is doing 2 entire passes, so my little 1.5" x 1.5" test took 20 minutes. I’m wondering if you could speed up the process by having the Layer 2 engrave settings remove only the excess Layer 1 (blue) material for the Layer 2 image, so the Layer 1 engrave then would be the union of both separations. First you would remove the white material to expose blue for both final layers, then remove only blue material where you want black. The laser assembly might do only one full pass and then a smaller set of movements for Layer 2.
It’s treating the optimization algorithm like a black box, unfortunately. If 3 layer material becomes popular and the laser power can be adjusted quickly enough, one could imagine doing an engrave in one pass with a new Glowforge mode that flips the laser between two power levels, assuming the same speed for both levels.
I will post my first real project when I get to it.