Rough Pontil Theory
People often assume that if a piece of glass has a rough pontil, then
it must be Blenko. They have also been taught that if it doesn't
have a pontil, then it can't be Blenko. Sorry to disappoint the true
believers, but this theory is incorrect.
Other American glass companies located in West Virginia left the rough
pontils on the majority of their designs. Bischoff, Pilgrim, Rainbow
are always found with a rough pontil. Ohio's Erickson Glass pieces
are mostly polished pontils but are sometimes found with a rough pontil.
The majority of Blenko designs can be found with rough pontils. Just
as with everything else, there are always exceptions to this rule. Some
designs were designed to have a polished base. Then some pieces had too
large of a pontil that made the piece wobbly. The piece was then taken to
the grinding shop to be ground and polished.
Please remember the first thing a Blenko collector looks at is color.
Learn your colors, learn rough pontils and polished pontils can come
later.
Sheared vase.
From the Illustrated Glass Dictionary
Pontil, Pontil Mark
The pontil, or punty, is a solid metal rod that is usually tipped with a wad of hot glass, then applied to the base of a vessel to hold it during manufacture. It often leaves an irregular or ring-shaped scar on the base when removed. This is called the "pontil mark."