I made large clay sculptures of matchsticks, adding detail into the burned top. To do this I looked at pictures of close-ups of burned matchsticks.
Once these were fired in the kiln they were much more solid. However, some did break and were glued back with super glue. The next step was to create the plaster casts.
To start off more clay had to be used. It was flattened and cut into same sized slabs. The matchsticks were pushed into the clay and the border was created by using
thin pieces of wood.
A barrier had to be created to get the plaster into a rectangular shape. To make sure it didn't leak out, clay had to be stuck in the corners. After a while the plaster is partially dried and this is when the wooden barrier is taken off. This had to be done carefully and at the right time as the plaster can stick to the wood and cause the cast to break (as I experienced with one of my casts).
Another important factor to consider is the consistency of the plaster.Too thin and it will never set and too thick it will set before you can even pour it into the mold. A good way to make the mixture is getting a container/bucket and filling it half way up with water (or as much water is needed) then sprinkling the plaster (not dumping) into the water. This has to be done at a fast pace, so it doesn't set, and until it sits on top of the water. It then has to be mixed, with a spoon or with your hand. It should feel like sticking your hand in double cream. It should then be poured into the mold as soon as possible.
The plaster casts turned out like this:
