A frame comes off the cutter with sharp edges and a chalky surface. It then goes into a barrel of birch chips and paste, and turns slowly for four days.
The first barrel takes the edges off. The second smooths. The third and fourth bring up the shine. Rushing any of them leaves a frame that looks fine in the shop and dull in a year.
After the barrel, each frame is polished on a cotton wheel by hand. This is the only step where the maker can still change the shape, and the good ones do.