Compression bits are often misused, but when used correctly they provide a perfectly clean surface on the top and bottom side of the material. The key is making sure the first pass depth is below the upcut portion of the bit to ensure only the downcut portion is touching the top surface of the material. If your first pass is contacting the upcut portion of the bit, there would be no difference in cut quality if you had just used an upcut bit. The tools used in this video are available on our web