The skin is washed repeatedly to remove the residual lime. The skin is attached to a frame with ropes that are attached to pegs mounted in holes around the frame's perimeter. The tension is controlled by turning the pegs. The skin is stretched and worked with a variety of semi-lunar blades when it is both wet and dry to produce the desired thickness, finish, etc. It can be further smoothed with sandpaper, pumice, etc.
Some manufacturers further modify the skin by applying various sizings, gessoes, etc.
Partial Parchment Making Bibliography Cains, Anthony. Gottscher, Leandro. 1993. Biblioteca Apostolica Vaticana, 1993. Reed, R. 1972. Ancient Skins, Parchments and Leathers.