Finishing Polymer Clay Objects

You've chosen colors, prepared the clay, put the pieces together, and cured your creation. It seems sturdy, but somehow it just doesn't seem - complete. Here are a few ideas for "finishing touches" for your clay objects.

Option 1: Sanding and Buffing
Cured polymer clay tends to have a matte - some might even call "dull" - surface. There is a way to get that surface to shine, though - with sanding and buffing.

The first part of this process, sanding, is done a bit differently from what you might expect. Polymer clay needs to be wet sanded. You need to use special sandpaper that won't fall apart when it's wet; this can be obtained at most auto supply stores. The sanding itself must be done under water. Why? If you've ever sanded wood you know that the process creates a lot of fine dust. If you sand polymer clay the dust you'll make is plastic - not something you want to breathe in. Wet sanding keeps the dust in the water and out of the air.

I've read books that recommend sanding under running water. I don't like this idea for two reasons: it wastes water, and it doesn't guarantee that all the plastic dust will stay out of the air. Instead, place the object in a container of water and sand it that way. If the object is very large you can always put it in the sink, or just sand one part at a time under water.

Start with a grit of about 400, which is fairly coarse, and work up from there. The higher the grit you use the smoother and shinier the surface will become. After you're finished sanding, buff the object with a piece of heavy cloth, like denim.

People who do a lot of sanding and buffing buy specialized equipment for this process, but that's not necessary if you're not going to do this much. Also, it can be hard to sand and buff tiny objects like pendants on large equipment. It's a good idea to start out with sandpaper and a buffing cloth. Then if you find yourself using this process a lot, or if your items are very large, you can invest in equipment later.

Option 2: Varnish
Sanding and buffing can give your items a beautiful shine. But if you've made something that's three-dimensional or that has a lot of curves it may not be practical; you wouldn't be able to sand all those crevices. In that case, consider applying one or more coats of varnish. If you use a gloss type you'll have the shine, and in any case your item will be more protected from wear.

You can find all different kinds of varnish, from the little bottles carried in craft stores to the large containers at hardware stores. All the water-based varnishes (not the oil-based kinds) will work with polymer clay. But some won't wear well; if the item gets a lot of use the varnish may eventually peel off. (I speak from experience here.)

The best choice for varnishing polymer clay objects is Varathane^TM. (This brand used to be called Rust-Oleum^TM and may still be found under that name in some areas.) It bonds with the clay and won't peel off. Check the label carefully, though, and stay away from the oil-based version; oil-based paints and varnishes may never completely dry when they're applied to polymer clay.

It may help to wipe the surface of your object with alcohol to remove surface oils (like the ones from your fingers). After that you can either paint the item or, if it's small enough, dip it in the varnish. Dipping is faster, but you need to find a way to suspend the object while it's drying, and put newspaper under it to catch the drips. You may also need to gently remove drips from the bottom of the object before they dry and harden that way.

Option 3: Glazes and Future^TM
You can obtain glazes made just for polymer clay, but in my experience these tend to peel just like varnish does. Some people like to use Future^TM, which is an acrylic floor finish. They say it "sets" nicely in the oven. I've never tried it; if you're interested in this option, check out the information on this Glassattic web page.

Final thoughts
It's always possible, of course, to just leave your clay item as it is. Finishing can detract from some "natural" effects, like those of rocks or stones. And if you've created a particular surface texture it may not be necessary to finish it.

Of course you'll be concerned about how your object looks, but don't forget to consider its intended use as well. Make your choice of finish on both those factors.