This page uses a number of photos from other websites or books as there are no parchment makers currently at work in the UK and thus unfortunately I have not been able to provide original/clear imagery.

The skins should be of the highest quality, from an infection free animal and free from blemishes.  The skins are shaved from the animal and dried (ideally in the sun). The processes that follow differ depending on whether the preparation is done entirely manually or whether there is machine assistance. 

This raw skin then needs to be softened in order to remove unwanted tissue, soaking in water for around 24 hours. Halachically the preparation or processing has not yet begun.  It is the next step that marks this.  The processor needs to verbalise their intention that they are putting the skins into a strong limestone solution bath (below left) for the specific purpose of the mitsvah.

This limestone solution is called sid and it is done to remove the hairs of the animal.  Halachically it should remain in the solution for four days, but it can be left as long as ten. 

Removal before the minimum 4 day period classes the skin as diftera and as such it is not valid for holy work.

After this the parchment is finally left to dry on the racks and when fully dry the skins are cut from the racks into a rectangular shapes (right) for ruling and use by the sofer.

Mordechai Pinchas