Square was conceived by Finnish (?) designers Erkki Pennanen and Kari Lilja. They submitted the aptly named biform typeface to the permanent contest organized by Mecanorma, the French manufacturer of dry transfer lettering sheets. Square was selected as a contest winner, and issued around 1972 in solid and outline styles.
About a decade later Barbara Holdridge picked it for her book design for Peruvian Textile Designs. For some reason, she didn’t use it directly, but rather drew Square’s letterforms by hand. Maybe this was done so that the lettering better matches the imagery of the Peruvian indigenous folk art, which is also squarish and geometric to some extent, but not drawn with perfectly straight lines either.