I was looking for a small sized woodgrain stamp to use for my polymer clay pendants but they can get pretty expensive and the grain is usually slightly larger than I want. Because of this I decided to make a stamp for my polymer clay out of polymer clay itself. It's actually pretty easy to do and produces a very nice texture without having to keep re-doing a texture for subsequent projects,
Step 1: Conditioning the clay
The first step is to grab one 2 oz package of polymer clay. You will only need about half of a package for the stamp (depending on the size of stamp that you want). I used white Original Sculpey clay for my stamp. I like the slight flexibility of the Original Sculpey clay for this project.
Then you will need to grab some tools to help condition, flatten, shape, and incise into the clay. I used an X-Acto knife, a green plastic knife, a few basic polymer clay modeling tools, and a pointy tool.
After you have gathered all of your materials you will want to condition the clay by cutting the 2 oz package into 4 pieces with the X-Acto knife. Then work each piece separately in your palm until it is softened. Then combine all of the pieces into one ball and keep working them together.
Separate the ball into 2 equal pieces and save one half for another project (or use it with your stamp.) Wrap the leftover clay in aluminum foil because polymer clay will interact with most types of plastic containers and sometimes plastic wrap.
This step is important because it makes the clay soft and mixes up the materials within the clay that makes it strong and non-brittle. Once you condition clay, you will never need to do it again. If you own a clay conditioning machine (pasta machine) you can use that. Make sure not to use anything that touches polymer clay on food though, because although it is non-toxic to use, it is not safe to be ingested.