Not Just Paint: Why You Should Prime Air Dry Clay Sculptures
Creating air dry clay sculpture calls for you to be a bit of a mad scientist: you experiment wildly with various media while using long-standing artist techniques to make truly fine art pieces. One thing I found is that if you're intending to paint your air dry clay sculpture, like any good artist, you need to prepare your substrate.
If you've done any kind of DIY-ing, you're likely familiar with prepping a surface. Priming is not just about sealing the material, but also creating a stable exterior for your paint. In this case, your substrate is clay and it should be primed (ideally) with gesso.
Gesso me this
Gesso is made of a combination of materials that I won't bore you with here, mixed into an acrylic base. Unlike acrylic paint however, gesso creates a toothy surface that paint adheres to easily. It is traditionally white, but you can also buy black or clear gesso. You can also tint it with a bit of acrylic paint.
The advantages of gesso:
- Relatively cheap - a tub/tube lasts a long time
- Can be thinned with water (in moderation) to preserve details
- Weather or temperature are not an issue
- Can mostly be removed if you mess up, and is generally forgiving
The Other Primers
Yes officer, I confess, I've used enamel-type spray primers from the hardware store. Guilty, as charged. They are easy to find and come in other colours, like brown. If you're making sculptures for your own pleasure, go for it. I switched to gesso due to the fact that it is an artist material and will not degrade overtime (plus spray painting is a b***h).
Some other disadvantages of spray primers not dedicated to art purposes include:
- Can be adversely affected by temperature or weather fluctuations
- Big learning curve to apply in thin layers and cannot easily be fixed once on (e.g. drips)
- The cans don't last very long, which ends up being pricier than gesso
Another one I have considered is house paint. It sounds like a good idea, especially since most of us have at least a couple of half-used cans kicking around. Sadly, the life expectancy of emulsion paint (often called latex paint in North America) is not great. Have you ever noticed that painted walls have a tendency to peel or slough off as a few years? Have you ever washed a painted wall and some paint invariably ends up on your sponge?
Even modern, high-quality wall paint applied with proper surface decoration can last maybe, what, 10 years? Humidity affects it a lot and whites yellow over time. Not ideal for artwork. You don't want to put all your hard work into a sculpture only to have it degrade after a short time.
Why Prime Air Dry Clay?
1. Uniformity: Air dry clays like Creative Paperclay (CPC) are water-based. Unlike epoxy clay or cold porcelain, the surface of CPC is porous. When you lay down the first layer of paint onto CPC, it soaks it up like a sponge and gesso will help you apply paint in a more uniform way.
Additionally, if you're using mixed media on your sculpture, for example your horse mane is made of a different material than the body, then priming will help to unify those elements before adding paint. It creates a more cohesive piece.
2. Sealing: Gesso creates a moisture barrier between clay and paint, and also clay and the outside world. CPC is water-based, and while it won't re-hydrate, it can be sensitive to humidity.
Sealing the surface is also very important if you use lots of water heavy paints (like watercolour) so they don't affect the clay layer. Plan on using oil paint? Remember that oil is corrosive, and you should lay down at least 3 layers of gesso to create a thick enough barrier.
3. Adhesion: Not only does it seal, gesso also helps the paints to stick to the surface better. Due to it's tooth (slight texture), gesso makes it easier for paints to stay on the surface. If your surface is too smooth your paint will not adhere well, and runs the risk of peeling off. This is especially important on very smooth clay bodies, like epoxy clay.
4. Strength: This last one should not be underestimated. Gesso is a like a layer of slightly flexible material over top of your work, and it can provide a tiny bit more reinforcement. Unless you're sculpting in bronze or stone, sculptures are fragile items, so I take any extra bit of strength where I can get it.
While a painter easily layers gesso on a flat surface, sculptors have the added challenge of curves and edges. For those of us who hate to brush a 3D surface, you can purchase spray gesso. I have used the spray gesso with success, though getting into crannies can be tough; however, due to my current studio set-up, painting it on is more accessible.
My gesso application onto air dry clay sculpture is pretty simple:
More often than not, I brush on 2 light coats of gesso because I like to keep some of my sculptural texture. I let the gesso cure at least an hour between coats to ensure the adhesion is maximized and I don't pull off any semi-dry layers.
Before I start the real painting, I let the gesso cure for at least 24 hours. This is because I often use very watery surface decoration, and I want to ensure the surface is ready to handle everything I'm going to throw at it.
If you would like a smooth surface, you can sand the gesso in between coats (must be totally dry!). If you do this make sure you use a very fine sandpaper. I suggest 220 grit on the first/second pass, and then move up to 400 on the later layers for super smoothness. Wipe down after sanding to get rid of dust. This method requires at least 3 layers and often more, but if smoothness is your aim, this produces great results.
Note: gesso is quite thin (consistency of a runny yogurt), so ensure the surface of your sculpture is as smooth as possible before you prime to save on layers of gesso and time sanding.
Priming an air dry clay sculpture is just one of the many steps you should take in constructing artworks that bring pleasure for many years. Don't be afraid to embrace your inner mad scientist and bring some tried and true artistic methods to sculpting with air dry clay. You might be surprised how well they work!