The branches are made of a mixture of materials seen upper left. Got a portion of it painted in flexible cement today, see right. Bottom left is a close up of a dried branch's bark-like texture.
Today I painted on one quart of pre-mixed FlexAll (Limestone, Ethylene glycol, Acrylic Copolymer) onto a selection of tree branches. It looks so much better than I thought it would. I thought I'd have to apply several layers and perhaps even press a real bark texture cast into the wet compound to get a naturalistic bark look. But it seems that this flexible cement-like material dries with just the right amount of grain in its surface all by itself.
Out of the tub, it's a sticky, butter-cream frosting consistency. I painted it on all the surfaces of a bit of the tree's branches, which are composed of a mixture of real twigs and branches (picked up during local wind storms), reinforced at the joins with masking tape and papier mache, plastic tubing, chicken wire, etc. By covering the whole thing with this unifying material the idea was to have the tree look as if it grew as it is, without being able to notice where the joins were created or what parts aren't natural. It already looks exactly as I would wish, and the illusion will increase further when layers of bark color are added, as well as the hundreds of leaves! I dragged the brush through the layer after about 30 minutes to get a kind of raked result. Who knew that was how to get the texture I wanted? Maybe this is how real trees are made?
I have another quart here and plan to buy about 3 more for Friday (right hand packed in ice from today's work) to finish this stage of the tree. Very exciting and fun for me to watch this action stage actually happen!