That's very interesting info there, Uncle_Riotous. I hadn't known about the concave/convex differences. What I did is that pretty much every day I'm at one of the local coffee shops. Since I telecommute often, the coffee shops are somewhat my workplace. So I borrowed a coffee bean from one of them and made a model. The center groove is still unfinished, as I've noticed often there's stuff in there that I guess joined the bean to it's other half. I did notice, however, some of the beans do have darker blotches, especially the more oily ones.

What I hope to do tomorrow during a break is try to model some of the stuff that's in the groove area. I do hope to model slightly different variations of the bean--adding imperfections--because no two beans are alike.

The material in the images here is something I had made for an earlier project. I just changed the color a bit. Someone has suggested the color should be lighter.

What I would like to do eventually would be to model a green (or red) coffee bean, like one sees in a photo of the beans still on the plant. I'm not sure of the scale compared to a roasted bean.

Tonight I did an espresso mug from one of the coffee books I have ("world encyclopedia of coffee") and I'm now wondering how to make the foam look authentic. I think there's a beer foam post somewhere here to look up.....

It's like for every idea there's always something to research. :-)