The process of Palimpsest was a common method of medium ''reclamation'' seen in the 6th Century AD. The term, from The Greek, means ''to scrape again''. So to, was this applied to illuminated manuscript makers and Scribes (Copyists). The process of creating the Medium used for making book pages required Vellum or sheep skin, which was dried and scraped repeatedly – to create a thin layer of material (which was similar to the later mass produced paper). Chemically treated and dried, it would often take many month to produce barely a yard. This coupled with the time involved with ''creation'' if an illuminated manuscript, was another reason why such books were expensive to own.
As a means to conserve Vellum, if a commission was canceled – or a mistake was made (prior to dry erasure methods of the 12th Century AD), the work was scraped again until the image or printing was gone. This caused several problems. The method of Palimpsest could only performed several time before the Vellum became unusable. Still, a skilled Illuminator or Copyist, was expected to make at least (1) mistake ''per year''. This helped lessen Palimpsest techniques, by and large.
However, improperly ''erased'' manuscripts have caused issues in ''modern'' discernment (translation) and well as ''revealing'' when exposed to modern x-ray equipment – previously ''hidden'' writings showing what was intended to have been printed (or erased).