The absorbed laser power is used to break the chemical bonds and crack up the cellulose molecules to their constituents (cutting by chemical degradation), generating a carbon based smoke and water vapour. The top and bottom surface of the workpiece retain unchanged whereas the cut edge is covered with a layer of residual carbon dust, which blackens the cut edge. The darkening of the cut edge depends highly on the density of wood, applying a high pressured air jet blows the loose carbon dust off and minimizes the discoloration of the cut edge.

Cutting speed and quality may change due to varied density in batches of wood or diverse water content from piece to piece or even in one piece (knots). Changes in density may prevent the laser from burning through. Plywood is far more homogeneous than "natural" wood and the cutting process more reliable and constant. Plywood with thermally unfriendly glues (phenolic based glues) and wood with a high content of resin are undesirable for laser processing. (Laser grade plywood is available from most suppliers)