Tuesday Tips - Relief Carved Models

I think that one of my favorite things to do is to create clay models and cast them in plaster to make molds. There is just something about the process that is satisfying.

I start with a blank piece of clay that I then transfer an outline of my drawing to. I use a small wooden knitting needle and find that it's best to start on clay that has passed the soft squishy stage. Most of my models are made from porcelain clay. But you can use any fine body of clay with no grog or sand. Grog and sand tend to make it difficult to get nice clean cuts as inevitably a little groggy bit will drag along your nice clean line and make an annoying scratch.

I then rough out the design using wire loop modeling tools and dental tools. Notice that the dragonfly isn't in there? I added him later using small coils of moist clay.

It's important to keep track of undercuts and remove them. An undercut will trap clay when you use your mold making it difficult to release your pendant from the mold. Might even be impossible. See that arrow? It's pointing to an undercut. I find it useful to hold the model under a strong light to see where shadows are cast. Hold your model as level as possible under the light and you should see where you need to clean things up.

This is the finished model. Most of the final carving was done when the model was in a leather hard almost dry stage. You may find as you are working with the model that it is getting a bit to dry. When this happens, try setting your model on a damp sponge and draping it with plastic for 15 or 20 minutes. Good time to get another cup of coffee :-). If you try misting your model with water you will tend to lose the detail you carefully carved.

The last step for me is to use very fine water colour brushes to smooth out tool lines. I dip mine and then ring them out with my fingers so they are barely moist. Just like misting, if you use to much water you may lose detail.

You can find modeling tools in most craft or hobby stores and at your favourite ceramic supplier. My set is fairly limited, a couple of different size wire loop tool, some metal scoop shaped dental tools,  and the best, my bamboo knitting needle.

Come back next week. I show you a couple of diffrent ways to make your plaster mold.