How do I tell if my glass is Blenko?

To tell if your glass is Blenko, look for the maker's mark, which usually appears on a label affixed to an inconspicuous area of the piece, such as the interior or bottom. The American glassmaker marked most of its pieces, but some weren't marked, and others may have lost their labels over the years. If you can't find a label, compare your piece to images found in Blenko glass catalogues available through trusted online resources. A certified appraiser or knowledgeable antique dealer can also be of assistance. Find a wide variety of Blenko glass on 1stDibs.