I just assumed he was on about laser engraving, seeing this is a laser forum.
Luckily I have experience with laser cutters. Using tape, will help prevent charring on the surface. But you need to use low-medium tack tape. You don't want the glue interacting, and it is easier to remove as well.
You can then proceed to lightly sand the surface like Jerry suggested.
In welding and several other fields of manufacturing, this is termed "heat-affected zone" or "HAZ". It can be reduced by using higher power for shorter durations, using a material with a higher damage threshold, using a material with lower conductivity, and dozens of other methods google would know about.