Q: I’ve never seen a glass plate this large. It’s 18 1/2 inches in diameter and is cobalt blue and silver and gold metallic. A little of the blue paint has worn off the back but otherwise it’s in good condition. Can you tell me who made it and how much it could be worth?

A: This is a large torte plate made by the Indiana Glass Company of Dunkirk, Indiana. The company was in business from 1907 until 2002. The pattern is Constellation Grape. Indiana first made Constellation, also known as Pattern Number 300 or Intaglio, about 1935. Constellation was made with a plain center as well as with grapes in the center. The pattern was made for several years but we haven’t seen one with blue and metallic paint. It was probably decorated after it was sold. In good condition, it could sell for $75 to $100.