Square/Circle figure/ground ambigram

A figure/ground ambigram, where the negative space in one word forms another word. In this case, the negative space in the letters spelling "square," become the letters spelling "circle." To add an extra level of complexity, the basic forms of the word "square" are constructed from perfect squares (with the exception of the "s" and "r"), and the letters comprising "circle" are formed from circles (with the exception of the letter "e").

This ambigram was selected for inclusion in Ambigrams Revealed, a collection of ambigram art from across the globe (p. 122).
Book by Nikita Prokhorov. New Riders, Publisher.

Ambigrams Revealed