Laser power and speed by material

Clear acrylic is transparent at 445 nm, the wavelength a blue diode emits, so the beam passes straight through without depositing energy. This is a property of the material rather than a limit of the machine, and no amount of power or extra passes changes it. Black or coloured cast acrylic absorbs the blue light and cuts fine, and a CO2 laser at 10.6 um cuts clear acrylic beautifully.

Use them as a starting point and never as a final answer. Optical power varies between machines with the same rating, lenses differ, air assist changes everything, and plywood in particular varies between sheets because of the glue layers inside it. Always cut a small test on an offcut from the same sheet you are about to use.

Multiple faster passes usually beat one slow pass when cutting. Each pass clears debris and lets the beam reach fresh material, while a single very slow pass dumps heat into one spot, widens the kerf, chars the edge and raises the fire risk. For engraving the reverse is true and one pass at the right power gives the cleanest result.

It is a percentage of the machine rated optical output, not of its electrical draw or its marketing figure. A machine sold as 80 W might have 20 W of optical power from four 5 W diodes, and the percentage applies to that 20 W. This is why comparing settings between machines only works when you know the real optical power of each.