When you make something from wood, it will need to be sealed in some way (usually with a varnish or wax) so that the wood fibers are protected against dirt and to prevent weathering. If you do paper art, you often need to seal it for the same reason. But polymer clay is vinyl and therefore does not need to be sealed. Let me repeat that. There is no need for a polymer clay sealer. For this reason, I really dislike using the term “polymer clay sealer”. It’s misleading.
Polymer Clay Sealer, Glaze, or Varnish?
As I stated above, polymer clay does not need to be sealed. Polymer clay also does not need to be glazed. We glaze donuts (yum!) and we glaze ceramics. Polymer clay is not glazed. I think this mistaken identity comes from the fact that there is a product called Sculpey Glaze, that gives people the impression that coating your polymer clay project with something is a necessary step. It is not!
There are times, of course, when you might want to coat your polymer project with a clear coating, either to change the gloss level or to protect surface treatments. You can learn more about that here: Do you have to seal polymer clay?
We do often use varnishes in this way, however, so I do prefer the term varnish when you’re using a varnish (as opposed to calling it a glaze or sealer). But generally, what most people want to add to their polymer clay project is a clearcoat, not a sealer.
Polymer Clay Clearcoats
There are many ways that you can coat a polymer clay project with a clearcoat. You can use varnish, wax, acrylic floor finish, dimensional glazes, and both UV and epoxy resin. All will work. You can also polish the finish to become shiny by sanding and buffing the polymer clay.
To learn more about polymer clay clearcoats and understand which one to use in which situation, have a look at this article: Understanding polymer clay glaze, sealer, and varnish.
Using Varnish with Polymer Clay
The most time-tested and least troublesome clearcoat for your polymer clay projects is probably varnish. You can use water-based wood varnish (also known as polyurethane) or you can use the type of varnish intended to be used to coat acrylic paintings. Either can work.
All types of varnish do have a certain learning curve. Brush strokes can be an issue, just as they were the first time you ever painted a piece of furniture or a wall. But keep practicing and you’ll get it.
One thing to know about varnishes is that they often have a chemical incompatibility with some brands of polymer clay. They very often never fully dry and remain sticky. This is because polymer clay is a plasticized vinyl. It’s always best to test the brand of varnish you have with the brand of clay you will be using. I’ve done this for you with some common brands. Here you will find how I tested 41 brands of “polymer clay sealers” for their suitability with polymer clay.
What About Resin?
Resin, both the UV curing variety and also epoxy resin, have both become wildly popular in recent years. Yes, you can use them as a clear coating on polymer clay. Be aware that there is a huge learning curve there. Resin is tricky stuff! There are also health concerns, because resin is highly allergenic, causing intense hypersensitivity reactions in some people. You can learn about using polymer clay with resin here.
What about using Spray Sealer with Polymer Clay?
Alas, most spray sealers don’t work very well on polymer clay. They never dry and remain sticky. All glossy spray sealers, glosses, and fixatives that I tried and tested have turned sticky on at least one brand of polymer clay. These seemingly perfect spray coatings are often recommended on newbie forums and groups on social media because they usually work nicely on Sculpey III, which beginners often use. But many, many projects have been utterly ruined by using this type of spray on your project. There are some sprays that can work, but they usually leave a pebbled surface, not the glass-like shine that is desired. You can read more about the topic here: Using Spray Sealers with Polymer Clay.
So What’s the Best Coating for Polymer Clay?
It totally depends! You need to understand the options so that you can choose the one that works best for what you are trying to accomplish and for how you want it to look. For some people this means resin. For others, it will mean sanding and buffing. Or varnish. Or dimensional glaze. They’re not all equal! Luckily, there are many choices, and many people have come before you to test them out. So read the articles linked here and choose one that will work well for what you want to do. Enjoy!
What about Sanding and Buffing?
You will find that many long-term polymer artists prefer the sumptuously beautiful finish of polymer clay that’s been sanded, buffed, and polished to create a flawless finish. There is no stickiness, no chemical issues, it’s not costly. But, like anything else, there is a learning curve. Everyone can “sand and buff” and lots of people will tell you to go “through all the grits” with wet/dry sandpaper. But learning how to sand properly and well will save you a lot of time and effort. The finish is a sensory delight and most people who touch and handle all these finishes will prefer the sanded and buffed one the most. But it does take time and effort to accomplish. If this is your kind of thing, the best information on the subject is my Sanding and Buffing course and eBook. You can learn about that here: Sanding and Buffing Polymer Clay. Here’s a little video showing what it looks like.
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