How can I combine two materials in Cycles? I was wondering if it is possible, using Cycles, to combine two materials.

For example, I have wood cubes which have a procedural wood material from Blendswap, but each of them needs a texture on it (a letter).

Actually, I duplicate my "wood" material and plug my texture on it.
So I have 3 materials (wood-A, wood-B, wood-C) while the "wood" part of the material is always the same, only the texture is changing.



Is there any way to make this easier to handle ?
Like combining a "wood" material (identical for the three cubes) with a different texture for each of them ?
That part you've labeled "wood" - group those nodes.
Then you can drop the group into each material: 1, 2, 3.
A group is a shared datablock, so changing its contents inside of one material changes it for all instances.