Book of Kells Project: White

Gypsum was used for white in the Book of Kells.

Now this was one I could justify buying from Amazon.  But...I already had zinc oxide laying around because I'm a ceramic artist.  And zinc oxide has also been used as a pigment throughout history. 

So I saved some poor Amazon sod from hunting down powdered gypsum in the warehouse and just used the zinc on hand.

Waste not, want not, etc.