I’ve experimented with this, too and it turns out you can do even stencils for 0.5mm pitch parts. I use 120um mylar films, rotate the stencil by 45deg and run the laser in raster mode.

Etch-a-stencil Courtesy Felix Rusu. ... Time: about 30 minutes Cost: $20 Difficulty: 4 out of 5. Instructions: 1. Slice the ends off a soda can and cut the cylinder open.