Knife edge buffs are designed to aggressively buff hard to reach areas. Yellow treated buffs are the most aggressive, treated muslin that helps the buff remove surface scratches. These buffs are all leather center.
Buffs for use of polishing motors- These buffs have rows of stitching to bind the layers of muslin together and make the buffs tighter and polish more aggressively than unstitched buffs. The more rows, the tighter and more aggressive the buff.
Yellow treated buffs contain a special impregnation that makes the material stiffer and more aggressive.