Quite recently my son had his birthday and his mother wanted to mark the occasion by making a personalized cake topper for his birthday cake. The figures she made were the cast of the Backyardigans. The reason for this is because our son loves this show so much.My wife started sculpting clay last year and from that time has really gained a lot of skill and experience, well in my eyes anyway and you could say I am biased because I'm her husband *snicker*
The work starts by first getting a copy of the characters in the series then studying how to mold the clay according to the characters shape. I read before that some clay artists actually draw the object they are going to build so that this way they are committing to memory the figure they want to sculpt, but my wife just goes directly to the job at hand.
Then the material of choice for her is polymer clay. Its basically like your ordinary clay that we used in kindergarten except that this can be baked to harden. Afterwards its shape will pretty much be permanent. For making the figures she uses the soft kind, specifically: Kato PolyClay, Scupley Premo and FIMO by Eberhard Faber. This type of clay is soft and not really good for the sculpting method of using a tool to slowly chip away at the material till the shape you want is left behind because it easily gives way when force is applied to it. For sculpting using a pin needle or other scraping tool it would be best to use hard clay like SuperSculpey firm.
The clay comes in a variety of different colors depending on what you want. You could use one color and paint it afterwards but for this build my wife used clays with different colors. Since the clay comes in blocks you have to knead and roll it a couple of times to soften it and make it pliable.
The secret material that she uses that's not really a secret is Liquid Polyclay by Donna Kato. My wife usually uses this as a glue to stick the small pieces of clay or other materials to add detail to the object, this is because using force to make parts stick can ruin the figure. Mixing even larger amounts of this up with the clay can make it into a paste like substance which can then be used for other effects in sculpting.
Then there are the weapons of choice above used to sculpt the clay. There is the slicing blade above that is used to cut the polymer clay as well as to push and align the clay during sculpting. Next to that is a dental tool used when filling cavities. You can actually pick up a lot of nifty tools from your local dental supply shop that you can use in your sculpting work. Dental work and sculpting work have the same purpose but slightly different goals. The third tool has soft rubber ends to it and is called a color shaper. It is usually used in oil painting, Clay artists however call it a "clay shaper". Then there is the very long and tapered Knitting needle which is also used for shaping. Last tool on the shot is a good old x-acto knife.
After the figure is made by the method of joining individual bits and pieces of clay together it is then placed into an oven and baked at the appropriate temperature (refer to your clay's instructions but usually its 30 min at 130C per 6mm thickness of clay). Its very important that you bake your finished figure in a well ventilated area and that you are not exposed to the fumes when baking. They are said to be toxic, that is also why you should have a dedicated oven or toaster for baking clay that won't be used in food preparation.
If the figure you made out of polymer clay is more than 1 inch in thickness, there is a tendency for the figure to develop small cracks due to the air bubbles embedded in the clay. The usual repair methods to fix cracks in polymer clay is to reapply some clay on the affected crack and re-bake it or blast it with a heat gun. One other method is to inspect the item for cracks right after baking. Afterwards, you use your fingers to close the crack by forcing it shut, then submerge the warm piece in cold water to permanently heal it.
In order to develop the skill for sculpting, my wife had to spend numerous hours practicing shaping the clay by using her hands and tools as well thinking of ways on how to use the clay in order to achieve the desired shape. It helped that somebody sold her a used book on sculpting by Maureen Carlson : How to Make Clay Characters
Below are some of the finished figures of the Backyardigans. Mainly Uniqua, Tasha, Tyrone and Pablo.
Here's the final piece with them and a clay figure (also made by my wife) of my son on top of the birthday cake. And no my son doesn't look like that... hehehe
You can also check out this tutorial on how to make a mold for clay figures.
