Home Cured Modeling Clays

Modeling Clay Types

Modeling clay is the most fun to "play" with. From faux beads to small figurines to plaques to Christmas ornaments to adornments for collages or scrapbook pages: every crafter can find an application for clay.

Home cured modeling clays, which you air dry or cure in your oven at low temperatures, are safe and easy to work with and are some of the most affordable crafting ingredients available.

Modeling Clay Basics

• With a few basic shapes (ball, cane, pear, teardrop) you can create almost anything.
• You can make clay molds; and then use the molds to recreate a design over and over.
• You can stamp impressions into clay; color it; texturize it; carve it.
• You can make it look like almost any hard substance from stone to marble to wood to bone.

The necklace and earring set pictured above was made using an antique Chinese "Prosperity" coin. The faux coral and jade beads were made with Sculpey III polymer modeling clay.

Crafts to Make with Modeling Clays

The choice of modeling clays and clay recipes is mind-boggling. It helps to understand the differences between the clays in order to decide which is suitable for your project.

I’ll narrow the field to general use modeling clays and exclude the exotic types like rose petal, cinnamon applesauce or coffee clay! That leaves three general categories: polymer; cornstarch base; and bread base.

Polymer Modeling Clays

The three main advantages of polymer modeling clays are: quick home curing; the consistency and range of color and texture; and less than 2% shrinkage when cured.

The choices of colors and finishes (such as stone, glitter, fluorescent and even glow in the dark) are wonderful. Some craft ideas for these types of modeling clay would be Halloween bracelets that glow in the dark or New Year's earrings in bright fluorescent colors.

The leading polymer clay brands are Sculpey and Fimo.

For reasons I will get into in Tips for Working with Polymer Clays, I prefer Sculpey. However, these observations apply to any brand of polymer modeling clay.

Pieces are cured in your home oven on low heat in just 15 minutes.

Polymer clays have very long shelf life and are stored simply by wrapping in plastic and keeping in a cool, dark place.

I’ve never had any harden in storage but if you do, there are diluents to make the clay workable again.

Cornstarch Based Modeling Clays

There are many variations of cornstarch based modeling clays. Some of the most popular are cold porcelain clay, Victorian salt clay, and pasta francesa.

I like the porcelain designation because cornstarch clays are pure white and, if sealed after drying, actually resemble fine porcelain, opening the possibility for many craft ideas and projects.

They require cooking to prepare. Cornstarch clays containing salt tend to be more porous than others.

Cornstarch modeling clays air dry; but drying can be accelerated in a warm oven.

The shelf life varies from one week to one month depending on the ingredients, storage temperature and humidity. Expect up to 30% shrinkage.

Bread Based Modeling Clays

Bread based modeling clays do not require cooking; they air dry; and will keep up to three weeks in the refrigerator. Shrinkage can be up to 50%.

The "no cooking or baking required" aspect makes bread clays the perfect choice for craft projects to do with your kids. Craft ideas would include Christmas Ornaments, clay Halloween pumpkins and similar projects. Cookie cutters work great with this type of dough. Just add a little paint or glitter and you're done.

As you can see, with polymer clay the shrinkage is small, 2% or so: with cornstarch clay it goes up to almost 33%: and with bread clay, it can exceed 50%!

As far as shrinkage goes, you can sometimes compensate by making your project larger than you want the finished product. If you want to reach exact dimensions, this might require some test samples.

Keep in mind that if you are making molds from which you will recreate a design over and over, the amount of shrinkage to expect almost doubles. If you make clay cast of a medallion that is 10mm in diameter, a cornstarch base impression could dry as small as 7mm and the medallions you make could be 4.9mm.

If you use bread base clay, the mold could measure 5mm and your clay medallions may be as small as 2.5mm. That’s a big difference! So compensate if necessary to get to the proper size.

Be sure to read my other articles about Home Cured Modeling Clays