This is a Japanese design technique called Notan. I am unsure of how long ago this technique originated as I haven't been able to find a lot of information about it. I was introduced to this activity recently by another art teacher.
These were made by some of my grade 3 students using one sheet of black paper and one sheet of white paper. It's great for a one-off lesson for shape, symmetry, reflection and cutting skills.
Students draw shapes around all edges of their page, the only rules being: the shapes go off the edge of the page and must be able to be simple enough for them to cut out. Then they flip out the cut-outs and glue them down. Simple but effective (what we all want!).