How do I identify Cambridge glass?

To identify Cambridge glass, turn the piece over. Many Cambridge pieces will display a marking that consists of the letter “C” positioned inside an equilateral triangle. Also, look at the rim of your glassware. Cambridge often ground rims flat but did not smooth them over. If you're still uncertain about the maker of your piece, consider consulting an experienced antique dealer or certified appraiser. On 1stDibs, shop a variety of Cambridge glass.