I noticed somewhere how someone said that a good model tree can be made from preserved root of some trees... Now I wonder can it be made by putting root of a tree into a mold and create a many casts of tree root ? I doubt it will end up good, but maybe someone can try... It is crazy enough so maybe it can work...
In my opinion too complicated (if not impossible for small fine branches). And way more expensive than digging some real roots - that way every tree you made stays unique as real trees shoud be. If you want (and have extra money) try to find tree armatures from Woodland Scenics. They're practical but not so realistic.
If you can find them, pull up small saplings of Birch/Beach (10-15cm´s tall)from a sandy soil..the root Systems will be very fine due to the sandy soil. Wash any soil off, let dry and spray with hairspray (any type) or, if anyone is getting rid of a box hedge (Buxus sempervirens or any of the variants of it) take the roots of that and treat them as above. Or..if possible, dig around any Maple or birch trees (the area just outside the area covered by the canopy) that are planted in a loamy soil (not heavy clay)..there will be tons of small fibrous roots..and taking a few from a small area won´t do the tree any harm.
Well I asked because I wasn't sure it can be done so I want to eliminate that option...I am sure that small branches of root will not turn out good...Never the less that was just a theory that is now eliminated...