Trees…. There are probably as many different ways to fabricate them as there are people fabricating them… Many years ago for a theatre production we took a piece of steel, bent it and covered with plywood and fabric, then muslin & glue to create birch trees. The edges of the muslin “peeled” off in a very realist looking way – but we were only recreating trunks of the trees. Otherwise, I have seen muslin, foam, chicken wire, cnc cut and nested, foam coat, sculptorcoat, supper 88, hardcoat and polygem all used to create trees – and virtually any other sculptural shape. Plus, I have seen many “recipes” for bark usually containing some mixture of glue or binder with sawdust or shavings. One of these days, perhaps we will all get together and try all of the materials at once and be able to compare the products to each other. Until that happens, I wanted to bookmark a few additional resources about trees and sculpting material on Poly Gem’s resource pages.
How To build a tree is their first offering, followed by a page of tips. They refer to using a press mold which EHow has an article on.
In terms of buying out fake bark, take a look at:
Quality Silks (also for branches and foliage)
Commercial Silk (also for leaves)
Retail Display and Props
Faux Stone Sheets also sells Flex Bark, a seemingly popular brand of fake tree bark.
Van Dykes Taxidermy offers pieces more suited for props. There are also other taxidermy supply sources that sell similarly sized small pieces of fake bark.
There is also several patents that are online regarding fabricating trees and making tree bark:
Peter J. Fritsch et al