I'm learning how to use my laser and having a lot of fun doing it. Right now it seems to be a lot of trial and error with settings. Does anyone know of a good repository for material/speed settings? for example i've been searching all over on the best way to engrave (etch) Acrylic and have not been able to find much other than my 2.8w laser should be able to do it, but a Co2 would be much better. Thanks!