I found this how-to web page for making a blade protector on the Pinewood Forge web site.
www.pinewoodforge.com
Following the suggestion I used cardboard from a cereal box, instead of bark from a birch tree, and was able to fashion a protector for a knife. The steps are easy, the design works well, and it was inexpensive. It seems a good fit for the form-follows-function, simple but elegant, handcrafted crowd. Next time I might use the Frosted Flakes box for the flashy colors and leave the colors exposed. For a beginner, it works for me. But I must confess I do like the protectors from little shavers for my palm tools.
Doug