I am test cutting some Adam's white board right now. 100w laser. Just a few short tests, but I've found that:
-500mm/s at 12% power (about 9W, according to my power chart for my laser) will barely cut through the paper alone (paper removed from foam for this test).
-500mm/s 15% power (about 9.5-10w), I reliably cut through the paper.
-500mm/s, 8% power (around 5w) will leave a light mark on the paper. It seems my laser won't fire below 8% power.
I'm trying to cut through the foam and paper now. I'm test cutting a 1" star. I'm having trouble cutting through the foam on the straights, without melting the foam at the corners.
I wish people would get one of Russ' Doohickeys to calibrate their lasers, and give power readings in Watts. Watts can be spoken universally across all lasers (once you have a calibration chart for yours). The % power number is essentially worthless, though. Not only due to the power of the lasers (40w, 80w, 100w, etc), but due to the wildy inaccurate power supplies/power readings in the lasers.