Greeting Card Set / Op ArtPepin Greeting Card Sets contain 20 folded greeting cards (2 x 10 designs) and 20 envelopes (10 x 2 designs) with matching designs, enclosed in a high quality box with a magnetic snap closure. The cards measure 150x210mm (6 x 8) when open and 105x150 mm (4 x 6) when folded. The designs on the cards and envelopes are based on masterpieces from important art & design movements.