Well, that used to be easier.
I finally got the Parquett-Oiled material to render from the Local Material Database after figuring out how to uv map the floor plane in blender (thanks for the UV mapping youtube tutorial:
http://www.youtube.com/watch?v=zv86PSPycPA.
But I'm positive that used to be easier. 'Mark seam, unwrap, select External, Local Material Database, Assign material, render'(I'm getting the blender UV steps confused with the Indigo steps)...I remember earlier all you needed to do to show a .jpg as a material in indigo was simply mark it as a UV in blender (I'm probably saying that wrong, but I think you know what I mean--whatever the steps were, I know I didn't need a youtube tutorial earlier).
There's gotta be an easier way. On in which you just (in blender) tell Indigo to use an external material, you select that .igm or .pigm from the Indigo Material database, and render.
scatman