For the past few years, medieval book historian Erik Kwakkel has been working with some of the world’s oldest books and manuscripts at Leiden University in the Netherlands, using his findings as important data for his ongoing research on pen trials. Pen trials are small sketches, doodles, and practice strokes a medieval scribe would make while testing the ink flow of a pen or quill. They usually involve funny faces, letter strokes, random lines, or geometric shapes and generally appear in the back of the book where a few blank pages could be found. Some of these doodles worked like signatures, as they were sometimes the only opportunity these scribes had to express themselves. Whereas other doodles were made hundreds of years after a book’s publication by people who were using them to study several centuries later, as just like we do now - even students back then got bored! Photo 1: Doodle by bored medieval school boy. A 15th-century doodle in the lower margin of Juvenal’s Satires, a popular classical text used to teach young children about morals. Photo 3: Medieval smiley face. Conches, Bibliothèque municipale, MS 7 (main text 13th century, doodle 14th or 15th century). Photo 4: Doodle discovered in a 13th-century law manuscript. Photo 5: Students with pointy noses. Leiden, University Library, MS BPL 6 C (13th century). Photo 6: Leiden, 14th-century doodle. Photo 8: Oxford, Bodleian Library (15th century).