Polymer clay and air-dry clay are among the clay variants that do not require firing. Therefore, it is perfect for beginners that are on a budget. When deciding on the type of clay to choose for sculpture making, it is important to know what suits your style. Moreover, factors such as time required for drying/curing or malleability also comes into play. So, what is it that makes air-dry clay different from polymer clay? Let us decode the differences between these popular clay choices!
Air-Dry Clay: What Is It?
Air-dry clay or self-hardening clay is a modeling clay variant that hardens when exposed to air for a while. Therefore, it doesn’t require baking in an oven or firing in a kiln. The primary components of air-dry clay are usually a combination of water, natural clay, and fibrous fillers like sawdust or paper pulp. Depending on the brand you like, the clay might also contain glycerin, preservatives, or polymers to enhance the performance and handling.
The drying process for air-dry clay can range from a few hours to 2 to 3 days, depending on the size and shape of the sculpture.
Polymer Clay: What Is It?
Polymer clay is comprised of synthetic materials that primarily include PVC or Polyvinyl Chloride resin mixed with additives and plasticizers. As opposed to air-dry clay, polymer clay doesn’t harden when left out in the air. It has to be cured at a high temperature, typically ranging between 265oF and 275oF, to harden permanently. If you feel this clay is perfect for your next project, you can try the Aestd-ST Polymer Clay. This set of 50 colors is non-sticky and non-toxic, which makes it ideal for sculpting purposes.
So, how are these two clay variants different? Let us find out!
Difference Between Air-Dry Clay And Polymer Clay
1. Durability:
When it comes to durability, polymer clay takes the cake. It is made from PVC resin and plasticizer, which, once hardened or cured, becomes very durable and hard. On the other hand, air-dry clay can break under pressure. However, you can make it more durable by sealing it after it has dried off completely.
2. Brittleness:
While polymer clay is durable, it can be brittle in comparison to air-dry clay. However, this happens if the curing process hasn’t gone right. Depending on the brand of clay used, the oven curing time can vary. So, make sure you read the label and fire the clay at the recommended temperature for the sculpture to cure properly. On the other hand, air-dry clay isn’t as brittle, given its composition that comprises fibrous materials. This gives air-dry clay a sense of flexibility even after it has dried out completely.
3. Firing Needs:
Polymer clay can only harden when cured in the oven, while air-dry clay hardens when exposed to air. Both air-dry clay and polymer clay do not require firing in a kiln. Even if you attempt to fire them in the kiln, they will burn down completely. However, among the two, only polymer clay has to undergo chemical changes in high temperatures to harden and achieve permanency which can be done in a home oven itself.
4. Waterproof Or Water-Resistant Feature:
Air-dry clay, once hardened, cannot be reworked as it loses its malleability. However, it does soften up ever so slightly if it is exposed to water. This means air-dry clay, although resistant to water, isn’t waterproof. The key is to seal it with varnish or any other type of sealant to make it completely waterproof. On the other hand, polymer clay can be left out in the air, and it stays malleable for years. However, once it has been cured to the point that it hardens, it becomes completely waterproof. You don’t even have to seal it.
Yet, polymer clay might lose its color when exposed to the sun for a long time. Sealing the surface helps retain the color for years with minimal to zero instances of fading.
5. Pricing:
Most air-dry clay brands come cheaper as compared to polymer clay. So, if you are just starting as a pottery artist and looking for a budget option, it is better to stick to air-dry clay and then slowly move to polymer once you have the budget for it.
Conclusion
Both air-dry clay and polymer clay are suitable choices for beginners who do not wish to invest in a kiln. While they do require some practice to figure out the workability, they can be great for daily practice, especially if you happen to have a spare home oven.
