Normal density plywood
This type of MDF that we used to do the kind of wood pallets signs lining. Material is high density, surface mount with a thin wood. The laser can be performed on these materials carving, but carved out of uniform and black color pattern, generally colored. Under normal circumstances you can through proper design, color plates of 0.5mm mosaic to get better results.
Laser dedicated density plywood
Some MDF is specially designed for use in laser engraving, carving out a pattern of uniform color, not colored also have a good effect.
clean
After carving MDF can use a damp cloth to clean the surface.
Colouring
You can use acrylic paints or alkyd. When carving color graphics can be set to 60% gray, the bottom surface of carving some pitting, to improve color adhesion.