He produced a series of eleven engravings for the Ars moriendi (The Art of Dying), a very popular devotional work. These were no doubt intended to be inserted into a manuscript copy of the book. The very controversial question of whether these were copies of woodcut versions of the same compositions in blockbooks was effectively solved in 1942, when Fritz Saxl published a set of manuscript illuminations using the same compositions found in the London library of the Wellcome Institute. These clearly predated all printed versions, all of which now can be seen to be derived from no doubt different versions of manuscript drawings in the same tradition. It has also been suggested that E. S. later designed the woodcuts for the earliest of the blockbooks, which are now seen as being created later than his engravings.
Read more about this topic: Master E. S.