"Celluloid Key Covering"/Bone

[Ellsworth]

Bone is porous in some places - the hpschd folks like that kind because it was
favored in the renaissence, being interestingly 'salt & pepper' marked.  But
for a piano they use the non-porous part, up in the joint - white as milk and
very uniform.  Any discoloration occurs when it has not been boiled out
properly - or bleached properly.  No orange staining with age like ivory.  No
ribby effect with wear.  ivory is great but not avail.
	Margaret