On some materials, particularly rough natural materials, the edges of text and graphics can look frayed or out of focus. Giving your images a hairline outline via a vector job can enhance and define those edges for a better result.
Vector enhancement is done using a high-speed, low-power vector job. Power should be set high enough to make a mark, yet low enough so as not to cut through the material you are working on. Frequency settings, with the idea being to mark a solid line, should be high enough to avoid making dashed lines. Frequency does not have to be set to the maximum. Your goal is not to vaporize the material, just create a burn mark.
This technique is especially suited to rough material where a conventional raster job doesn’t create defined edges, like rocks and rough-grained softwoods. It is particularly effective on rough natural fabrics and materials such as those found in welcome mats.
—Jim Puentes, COOLaserCraft