Keith â€” Lovely â€” best photograph of a Walsh mother of pearl crackle effect yet. :hiclp: :hiclp: :hiclp:
It clearly shows the thin inner layer (the first, tiny gather was of white or opal glass, probably a lampshade glass) had a slightly lower melting point than that used for subsequently building up the thickness of glass for the piece. The effect is usually found around re-shaped rims, where the glass was both cooling quite quickly and subject to considerable bending stress.
Did you see my Walsh mother of pearl on Sunday (right side of my stand, top shelf)? Only two pieces had the crackle effect, neither as easy to see as yours, and none had the luxury ground out and polished pontil scar finish. :spls: