A color glass art piece featuring Frank Lloyd Wright's window design. I purchased this a while ago at an exhibition. It's a set of cards and envelopes, with three sets in total. They have aged, and there is some yellowing. (See photos) I will pack them using recycled materials. - Design: Frank Lloyd Wright window design - Technique: Color glass and copper sash - Size: 15.5 x 8 cm - Source: Collection of the Art Institute of Chicago - Year: 1915 Thank you for looking.