In 1388 a charitable merchant in Nuremberg named Konrad Mendel founded a pensioners' home for elderly craftsmen from that city. In 1425 the foundation began a chronicle that featured a comemorative portrait of each pensioner when he died. The craftsmen were portrayed working in their former professions. Another philanthropist, Matthäus Landauer, founded a similar house and began another book of portraits in 1511.
These house-books, as they're called, are an incredible source of pictorial information about medieval trades, crafts and tools. You can now find all the images from them in one place on the internet, organized by occupation, tools, materials and products.
Check them out here.