Sure, I'll go over how I made this (it's really simple, almost as simple as you can get). I only recently learned some of the tricks I used.
Here's the obvious boring stuff:
- Take foam-core, cut into a rectangle (you can get it at Wal-mart near the poster-paper (giant construction paper).
- Measure the acrossways lines. Using a ruler, score the cross things good with a pen (or anything pointy, really). I went over each line three or four times pushing decently hard, I'm not sure if that was necessary.
- Measure the up-down bricks from the side, and score the brick-edges on every second row. Then do the same, moved over by half the brick width, and do the rest of the rows (basically, stack them).
Then comes the fun. I was looking around for something with an interesting pattern. I looked at my fruit bowl beside me, and had a stroke of genius! I took out a peach, ate it, washed the pit, and voila! A nice texture.
- Using a peach core (a rock works too, or anything hard with a well defined texture), imprint the foam all over.
- Using watered-down black paint, paint the entire thing. Make sure it's thin, so you don't fill in the details, but make sure you cover everything.
- Once the black dries, you might want a second coat of black, depending on how it looks.
- Take a gray paint (I used one that's ~50% gray), and brush it over. You should make sure you don't have too much on your brush, and spread it out a lot. You want to make sure you have some black showing, especially in the cracks.
- Take a off-white paint (cream-colored, or similar), and brush it over even more lightly (ie, with less paint on the brush). It should cover most of the surface, but very thin
- If you want, take a dark-green paint and add some mold. Same thing as before, with very little paint on the brush (more if you want it defined) do a few patches.
