When it comes to sculpting few materials are as popular as polymer clay. Easy to use at any age and easier to cure than other traditional materials like clay; polymer clay stands out as the most practical modeling material on the market. However, even polymer clay has its secrets and peculiarities and that’s what we’ll be going over today.
Compared to other similar soft materials like play-doh; polymer clay stands out due to its need to get “cured”. Curing refers to the act of baking the clay so it hardens and loses its malleable nature. This ensures that projects done with polymer clay can be long-lasting and solid without demanding any complex hardening process. However, due to that many people wonder how to bake polymer clay properly.
In todays article we’ll go over all the important information you’ll need to learn how to bake polymer clay. Ranging from why you need to bake it in the first place, to the right tools and oven for the task and even some extra tips and tricks that will improve your finished models. Polymer clay isn’t hard to master but, like everything else in life, it has its own needs and considerations. Continue reading so you can bake your creations like a pro.
Why do we bake polymer clay?
Polymer clay is a modeling clay largely made of Polymer Polyvinyl Chloride or PVC; which most of you know better as plastic. To be exact not all plastic is PVC, but PVC is the third most popular plastic polymer in the market so a lot of the plastic in our daily lives is ultimately PVC. It’s thanks to this composition that properly baked polymer clays are so strong and resistant. By baking polymer clay it starts to lose its malleable properties and becomes more like plastic in texture. But how exactly does all of this work?
When anything gets heated or cooked one of the main effects is that it begins to lose water. Water evaporates very easily so it’s one of the first things that any material loses when it gets baked. As polymer clay loses water it hardens, losing its ability to be molded and instead takes on a rigid state closer to traditional PVC. In short, it’s designed to only get hard by losing water and that’s why baking is such an easy way to do it.
Technically speaking any way of heating polymer clay will work to harden it. You’ll be able to find tutorials to harden polymer clay with heat guns, pans and even boiling water. And in broad terms, all of these options do work. The reason baking is preferred is mainly due to convenience. Most households have an oven at home and letting an oven do its work is easier than using a hairdryer for hours. So baking is overall just the most practical way to heat polymer clay and this is why it’s considered the industry standard amongst most manufacturers.
Now that we have cleared up why polymer clay needs to be baked let’s properly explain how to bake polymer clay like a pro.
All the tools you will need
If you want to learn how to bake polymer clay the first thing you’ll need is an oven. What is the best oven for baking clay is a contested topic, with various differing opinions on the matter. We’ll go over the various options with their pros and cons, but keep in mind that at the end of the day any oven should work.
The first question most people ask is if they can use their home ovens for clay projects. And in short: Yes you can, it’s likely the best option to boot. Traditional home ovens have a lot of room which is wonderful when modeling, as more portable options tend to limit the size of your projects. Additionally, home ovens have pretty stable temperatures which ensure your project won’t get over or undercooked. In pretty much any situation your regular oven is the best pick, and this makes a lot of sense. Polymer clay is meant to be easy to use and cure, so logically it would be designed with the most common kind of oven in mind.
Some people worry about the potential side-effects of cooking polymer clay in their traditional oven due to its unique composition, but ultimately it’s a safe process. Even when it’s overcooked polymer clay doesn’t burn directly, you’d have to go over the top with the temperature to get smoke. And even if this happens the smoke clay causes is as bad for health as the one you would get from burning most foods. Polymer clay doesn’t cause any toxic residue so it’s perfectly safe to use your oven both for food and modeling.
Smaller portable ovens are also a popular option due to their simplicity. They pre-heat fast, are easy to set-up, and take little space. However, the biggest issue with these ovens are temperature spikes. Smaller ovens don’t keep their temperature as stable as larger models, and heat isn’t always distributed evenly. This means that your models might end up over and undercooked at the same time. If you insist on having a separate oven for your modeling then it’s better to invest in a tabletop convection oven. Convection ovens heat through a flow of air, which means that the entire oven has a stable temperature. On top of that their work area tends to be larger and offers much more vertical space than toaster and portable ovens.
Besides an oven itself, the most important tool you’ll need is an oven thermometer. The simple fact is that built-in thermometers don’t tend to be all that accurate and often they give inexact readings to simplify cooking. Oven thermometers are fairly affordable and you don’t need anything fancy, you just need an accurate way to read the temperature.
Last but not least you need your polymer clay and a base for your model. You can use any tray or dish that is oven-friendly, but many modelers opt for a ceramic tile. Ceramic has a unique way to disperse heat and that makes it a great base both during and after the baking. It’s not an absolute must but it’s a great option if you have it. However, as we said above, make sure that anything you use as a base will be fine in an oven.
Proper baking technique and temperature
At the end of the day baking clay isn’t that different from cooking food or anything else you would use your oven for so, if you know how to use an oven at all you already know how to bake polymer clay!
The first thing you need to do is to have your model ready in your chosen base, check its dimensions and make sure it fits properly and safely in the oven. In general, you want to have some extra space for safety. You don’t want to accidentally bump your model or your hand into a resistance or heat source. So be mindful of your oven size before you start sculpting away.
Once you are sure you can insert and remove the model safely from the oven it’s time to leave it aside for the time being. Right now we need to pre-heat the oven. If you aren’t a cooking aficionado this means that we need to make sure the oven is at the right temperature before we put anything in. This is where the oven thermometer we asked for will come in handy. Set up the thermometer and calibrate your oven to roughly 265 degree Fahrenheit. Give it some time and then check the thermometer, if the temperature is correct then you can continue. If not, tinker with the settings a bit, as we said before oven settings don’t tend to be as accurate as they pretend to be.
Once the temperature is right it’s time to place your model in the oven. Make sure to wear gloves and proper protection at this point, 265 degree Fahrenheit is nothing to scoff at. Also, try to position your model as centered as possible, being as neutral as possible ensures heat distribution is more even. Time will vary depending on the chosen brand and the size of the model but, we’ll give you a rough formula below. Once you are done all you need to do is to take out your model and let it cool down. After a few minutes, your model should be at room temperature and properly cured.
How long should I bake polymer clay?
Knowing the precise time each model requires is a unique science, but it mostly comes down to two main factors: Size and Brand. Brand should be fairly self-explanatory. Each brand of polymer clay has its peculiarities and this means that their recommended baking times vary. That said size also plays a large role. Baking polymer clay is almost the same as baking any meal, and any cook will know that large foods run the risk of being undercooked in the center. Polymer clay doesn’t need to be consumed but, it still needs that even cooking process. If the outside of the model is solid but the center is still malleable and soft your model will crumble or at least remain frail. So, we have to carefully consider the size of the sculpture to make sure it’s baked properly.
Each brand offers its own suggested baking times for a solid finish and you can easily find this information on the package or online. However, there are a few things you need to take into account with these numbers. First of all, they tend to undersell the time it takes to get an ideal texture. If you want to get a solid model in your hands you’ll likely need to cook for longer periods than the packages suggests. And on top of that those times don’t work for all sizes. There’s no industry standard per se but, clay pros have made their calculations to ensure the perfect texture. Treat the suggested time as the time you’ll need for each 1/4th of an inch in thickness.
This might sound complex at first but, it’s way easier than it sounds. Let’s assume you are using a brand like Kato which recommends you to bake it for 30 minutes at 275 degree Fahrenheit. Now, let’s assume that your model at its thickest is half an inch. Since the suggested time is 30 minutes and your model is twice as thick you should cook it for double that amount of time. Based on the brand these times will vary considerably, and some require less than 10 minutes per 1/4th of an inch but, this is a reliable measure in general.
And like we said above some brands tend to undersell the times. So as you bake more clay models you’ll be able to find the right baking times for you. Everything in life comes with practice and this isn’t the exception.
Additional tips and tricks
The first thing you should keep in mind is not to be afraid to overcook clay. Polymer clay is far more resistant than it looks and provided you are using the right temperatures it won’t get scorched. Most clay aficionados tend to bake their models well beyond the suggested time so there’s room to experiment.
Related to the above is the idea of multiple bakings. A single model might have parts of vastly different thickness, or use various brands at the same time. If you are afraid that their different needs might cause scorching or deformation when baking then you can bake your model in batches. Take the main body and bake it on its own. Let it cool down and then add the other pieces and bake according to their needs. Bringing back your model to room temperature prevents damage, and baking in batches makes sure every material is cooked to its own needs.
If you bake smaller projects like beads and can’t keep them in place then we have the perfect tip for you. Grab two aluminum foil pans and some paper. Take one of the pans and fold the paper diagonally on it, this gives you a base for each piece. Then take the other pan and put it on top like a lid, then clip it together. You can cook it this way and not only will the pieces stay put but you’ll also get a more even temperature inside the aluminum.
And of course, the most important tip is to experiment on your terms. We have shared the general guidelines with you but, the more you bake, the more you’ll be able to come up with your own tricks. So keep modeling, keep baking and share any of your discoveries with us. Don’t forget to check out our page for the best paint for air dry clay. Then you’ll be ready to paint your model once it’s baked.
I’m a stay at home mom with our two kids. I really enjoy doing crafts with my kids however, that is typically a challenge with how limited their attention span can be and how messy it gets. So, I’m always looking for ways to make crafting an enjoyable experience and creating fond memory for all of us.