These pieces took over a year to hunt down and collect as a set--quite difficult to come by, and I had to have one of these pieces located in France for me. These lithos are printed in Holland are of the highest craft possible. Pieces are stone litho printed and are mounted on linen. They have wear and crackles in areas, but that is expected with charts this old. They are quite amazing as a set and without a doubt add visual punch to any collection. Originally used as a teaching tool they are so visceral and powerful to look at that they are works of art in their own right. Each chart measures 52" x 57" and are sold as a set.