Instructions
Look for colorless glass. Most pieces in the Fostoria American pattern are clear with few exceptions. Pieces in the Cube pattern are frequently pink or green.
Check for a fire-polished surface. Fostoria American glass has a smooth finish because pieces were returned to the furnace to soften the edges. Whitehall Indiana glass has a rough finish because the pieces were not fire-polished.
Count at least three mold marks. The majority of Fostoria American glass has three seams with a few rare exceptions. Whitehall usually has two seams.
Identify Fostoria American glass by the ground bottom. Feel for a flat, level base rather than a pressed bottom.