Subdued textures are all the rage now in app visual design. I've been making mockups for a simple financial app. To indicate wealth, I figured a leather texture would be suitable. Leather is expensive, and also associated with money because of wallets. Not having much luck in making good use of any leather textures in my screen design, I started getting interested in the material itself.
Each cell controls all the pixels nearest to it.
To emphasize the borders, for each pixel I checked about a hundred random nearby pixels and saw how much competition there was around that area. The more competition the darker the pixel. Unintentionally I got subpixel-accuracy rendering too, since this is a stochastic sampling method. The result is a greyscale picture I can use as a height map for the cells.
That's my version of leather. While researching about this, I came across an interesting Wikipedia entry on how leather was tanned in ancient times (it involves urine, feces and brains). I also ran across a cool article about how this cell-style procedure can be used for procedural computer game map generation.