While I was in Michigan over the past week, I got to play with i3 Detroit's new laser cutter (affectionately known as "Bumblebee"). When my friend Roger showed me how to use it, he mentioned that the laser cuts away part of the material, so the finished part will be slightly smaller than it is in the file. This lost material is called the "kerf" of the laser. To complicate matters, the size of the kerf depends on the material being used, and the power settings of the laser.