The making of parchment:

'and stand them in water for a day or a night. Take them and wash them until the water runs clear'

The skins are throughly soaked and swell up. The lime can then penetrate deeply into the skin. The salt that is rubbed into the skin whilst it is being flayed is washed out, as well as dirt and blood particles. A poorly treated skin must first have the fat and any remainig flesh removed. If this is not done then there will be ugly spots where the blood has soakes into the skin. Where too much flesh or fat is left on the skin then the lime cannot penetrate evenly. The intention is that at this stage, the swallon skin must have a regular open structure across the entire area.