Wooden wedges have been used by climbers for a long time. Most were home made but many early Sporthuases in Europe carried commercial versions with refinements like beveled edges, grooves for the cordage to lay in, and sometimes channels to accommodate stacking pitons. Our wedges are from Germany and were probably used in the early 1970s. Generally a harder wood type should be used for wedges intended for hammering on. I have two wooden wedges, made in Colorado by Harvey T. Carter, that were just simple chunks of pine 2-by-4 with webbing to clip into. They look terrifyingly soft and fragile but he used them as large jam nuts and occasionally gave them a whack with his hammer to set the piece securely. These European wedges are much better made and could probably even be used multiple times if needed.
The largest wedge in our collection can also be used in a “cam stacking” application. This is a rather insecure technique where the wedge is used with a camming device in order to increase its effective size range. Basically sandwiched between the cam and the wall of the crack. Care has to be taken when weighting such a placement.