The International System Of TYpographic Picture Education (Isotype) was a visual language system developed in the 1930s by Austrian scientist Otto Neurath in an effort to standardize and contextualize images for use by the (largely) illiterate proletariat. The designer of this language was German-born Gerd Arntz, who used basic shapes with small variations to produce visual models that are meant to convey meaning despite barriers of language and culture.
The prints were carved into linoleum stamps created by Arntz. While there are some 4,000 Isotype symbols, you can check out about 600 of them at the Gerd Arntz web archive. Some of the designs are quaint relics of a different time, but others are still poignant and surprisingly vivid and imaginative.
images from Gerd Arntz Web Archive.