Michael sez, "Apparently medieval Russian schoolroooms used birch bark for things like writing practice. Erik Kwakkel, medieval book historian at Leiden University, Netherlands, has some charming photos of stick-figure illustrations on bark by kids who, like kids everywhere, got a bit bored with the lesson and started doodling in the margins. There are links to more images (and an interesting scholarly article) at the bottom of the post."
The most special items, however, are the ones shown above, which are from a medieval classroom. In the 13th century, young schoolboys learning to write filled these scraps with alphabets and short texts. Bark was ideal material for writing down things with such a short half-life. Then the pupils got bored and started to doodle, as kids do: crude drawings of individuals with big hands, as well as a figure with a raised sword standing next to a defeated beast (lower image). The last one was drawn by Onfim, who put his name next to the victorious warrior. The snippets provide a delightful and most unusual peek into a 13th-century classroom, with kids learning to read – and getting bored in the process.
Medieval kids' doodles on birch bark [Erik Kwakkel]