Your project should be finish sanded and sealed before laser engraving. Sealing is necessary to prevent spoke staining of the wood, unless this is an effect you desire. After engraving, you may LIGHTLY sand the surface and then apply your final finish coats which will also seal the engraving. Over sanding may damage the finer detail in the engraving. After finishing you may either leave the engraved area it’s natural laser engraved color or color fill the engraved areas.