Maurits Cornelis Escher is the creator of Concave and Convex, and he is one of the most interesting artists in the 20th century. One may like his paintings or not, but we must all agree that he is unique. In fact, most people are able to identify his work as soon as they see it, even if they don't know the name of the painter. Perhaps they just know he was the Dutch graphic artist that painted impossible stairs, upside down rooms, strange reflections... However, when they see one work, they know it belongs to him.
For that reason, we can say that he is a quite popular artist. The M.C. Escher Foundation organizes exhibitions with his works regularly, and they always attract thousands of visitors. In fact, there was an exhibition in Madrid in 2017 for 8 months that showed around 200 works by Escher. It was one of the most visited in 2017.
Concave and Convex and other dichotomies
Escher got his inspiration partly on Mathematics and Geometry. Symmetry is a constant in the images he invents. For that reason, many of his paintings have a dichotomy in the title, like Concave and Convex in this case. However, we also have...