What is air-dry clay and how is it different from polymer clay?

by Mary in Oregon

Let me start by saying there's a huge variety of no-bake, air-dry, self-hardening clays!  Because of this variety, making a generalized comparison to polymer clay is difficult.

There are basically 3 types of clays for the home hobbyist... oven-cured, self-hardening and non-curing.... BUT..... the clays could also be grouped as oil-based, wax-based, resin-based, water-based, stone and cellulose-based.* (see Wikipedia definitions for more detail)    Polymer clays are not actually "clay" and must be heated to cure.  Although there are some air-dry & self-hardening clays containing polymers they are usually not referred to as "polymer" clay.  Oil and wax-based clays are the Plasticine clays often used to create clay animations.  This type of clay stays flexible (re-positionable) and it never hardens.  If heated, it will melt.

The no-bake, self-hardening clays are often water-based but some are polymer-based. Most will air-dry to cure but some cure with a chemical reaction. Hundreds of new brands and new formulas of no-bake clays have recently become available and this "new clay" is increasing in popularity every day.  The Air-Dry-Clay Yahoo Group and The New Clay News are all about this type of new clay.

*Note:  Clays that require a kiln to be cured aren't included in this discussion.  These are often referred to as earthen clay, ceramic or porcelain.  There is also a kiln-fired paper clay  (used by potters and ceramic artists)  which should not be confused with air-dry "Creative Paperclay".    


What are the most popular brand names of the new clays?


For purposes of  the New Clay News, we consider air-dry clay to include all the commercial brands of self-hardening, no-bake clays plus homemade clay recipes such as cold porcelain and papier mache. This includes brands such as Creative Paperclay, Delight, Makin's Clay, LaDoll, Hearty Clay, Deco ClayCraft, DAS Pronto, Apoxie Sculpt, Lyra, Artista, Angel, Aves, FormoFit, Darwi, Flumo, Lumina, Celluclay, Sculptamold, Cold Porcelain, Crayola Model Magic, Crayola Air Dry Clay, Sculpt It, Paverpol, Alley Stone and many more brands.


What's the difference between polymer clay and air-dry clay?


Oven-cured polymer clay will be plastic like, waterproof and durable if cured properly. The finer quality brands of air-dry-clay harden to a matte, smooth and very durable finish but must be top-coated and sealed because most no-bake clay is not water-resistant (there's a few exceptions). Some of the softer brands of air-dry clay will cure to a soft or flexible finish rather than the smooth, hard finish.

You can drill and sand cured polymer clay. You can also drill and sand many of the air-dry-clay brands such as Creative Paperclay or LaDoll, however, there are a few brands that dry too brittle for drilling and will crack. The majority of air-dry clays are non-toxic and child-safe whereas polymer clay has a few precautions with it.

Polymer clay is available in hundreds of colors but most air-dry clay is available in white only and must be pre-tinted or painted after curing. There are, however, a few air-dry clay brands available in colors.  Most of those are the softer air-dry clays. With polymer clay you have to be careful to keep it covered because it picks up every bit of dust in the air. That's not a problem with air-dry clay, however, you must keep unused clay covered to keep it from drying out!

Which clay is better?

Neither is "better" than the other...it just depends on which is better for you and what you like to create!   It takes a bit of experimenting to find the brand of clay that suits you and your sculpting needs the best. Unlike polymer clay, where the clay characteristics are generally similar from brand to brand, the characteristics and quality of air-dry clays can vary drastically. Some clays are soft and marshmallow-like, some are stiff. Some are very durable when dried while some actually stay soft when fully cured and are easily dented or scratched. Some air-dry clays are made with a natural stone based formula, some are paper based, some are even polymer based. Their self-hardening formulas are the main thing they have in common. The quality varies from brand to brand also. Everything from 'school grade' to fine-textured artist's grade. Be wary of brands marketed to young children. That probably means the clay will not be suitable for fine art.

Are no-bake clays easy to use?

Most polymer clays must be kneaded prior to use, however, the majority of air-dry clays need very little, if any, kneading and conditioning. The resin and polymer-based air-dry clays are usually the softest clays and easiest to use.  However, the soft clays are not very suitable for fine detail sculpting but are very popular for creating clay flowers. Softer air-dry clays are often available in a variety of colors where other brands are white only (some off-white or gray, some terra cotta). There are a few natural stone-based clays that are nearly as stiff as polymer clay and take fine detail beautifully. These type of clays are very popular with doll makers.

How can I learn which clay would be better for my own art?

Because there's so many different brands and types of self-hardening clays, there is an awful lot to learn. If you are used to working with polymer clay, it will take some practice and some experimenting before you find the no-bake clay that's just right for you. The best way to learn is to join our Air-Dry-Clay Yahoo Group, where we have many generous members willing to share their expertise and experience.  We also have a page here at New Clay News devoted to describing the characteristics of each brand.  If we've missed listing your favorite brand, please let us know!

Mary in Oregon