The art of crafting with bark tan is highly developed and takes many forms. It is well covered elsewhere, so we’ll just introduce you to the different possibilities and sources for learning more. It is all based around using the heavily tanned hides that are still produced on a large scale.
The art of leather carving is probably the most popular and highly developed of modern leather crafts. Sharp gouges, knives and stamps are used to carve away the leather to various depths and at various angles to produce beautiful and intricate designs. It was re-popularized in the ’50s by Al & Ann Stolhman, who have written numerous books on the subject that are available through Amazon.com. There also is an entire magazine devoted mainly to this art known as The Leather Crafters & Saddlers Journal. It has a circulation of over 8,400 people. You can get a hold of them at 715 362-5393, or email: firstname.lastname@example.org. There is also a large website for the The International Internet Leathercrafter’s Guild, which is mostly based around this type of leathercraft.
One really cool thing you can do with bark tanned skins is known as “cuir bouilli”, meaning boiled leather. Here’s a description from R. Reed’s Ancient Skins, Parchments, and Leathers:“Wet, vegetable-tanned leather begins to shrink above 75 degrees Celsius and so lose its shape. After thorough softening in water at ordinary temperatures the leather can be formed or moulded into the most remarkable shapes which on drying retain a fair degree of permanence. This shape can be set more permanently by drying under moderate heat, the skillful choice of temperature determining the degree of rigidity obtained.”
“A quicker process which produces extremely hard and rigid articles is to dip the moulded shape into boiling water for about 20 to 120 seconds. This partially melts the tannin, allowing them to flow and redistribute throughout the fiber network. On cooling, it turns into a tough, three-dimensional polymer network or resin, not unlike more modern materials such as Bakelite and the aminoplastics.”This technique has been used historically to make anything from leather canteens to armor to intricate masks. You can read more on the web about the interesting experiments of a group of Medieval re-enactors experiments with cuir bouilli.