If you're getting started in polymer clay, there might be a few things you’d like to know about baking before you jump in. We’ve got you covered with answers to common questions and some insider tips for you to keep up your sleeve. Happy baking!
1. Do I need to bake polymer clay?
The answer to this one is short and sweet – yes. Polymer clay needs to be baked in an oven or it won’t harden. The good news is that we have plenty of baking tips to help make it a nice, smooth process.
2. Condition your clay
First things first, before you start sculpting it’s a good idea to condition your clay. This simply means kneading it or putting it through a clay press until it softens. The reason this step is important is because it will make the polymer clay easier to work with and will help prevent it from becoming brittle once you’ve baked it.
3. Reducing air bubbles in polymer clay
If air gets trapped in your polymer clay it can cause air bubbles to form. These are tricky to fix once your sculpture is baked, but there are a few things you can do early on to remove them. When you’re conditioning your polymer clay, put folded areas through the clay press first to force out any trapped air. You can also keep an eye out and pop any air pockets using a knife or pin. Lastly, firmly press and compact your polymer clay where you can.
4. When is polymer clay ready to bake?
Polymer clay is ready to bake whenever you’re ready. You can bake it straight away, wait a few hours or come back to it the next day. It’s really up to you.
5. Know your oven
When you’re baking polymer clay, you’ll make life a lot easier for yourself by using a reliable oven. If it’s not the temperature you’ve set it to be, you can end up under or over-baking your clay.
Here are some quick steps you can follow if you’re using our Make n Bake Polymer Clay:
- Preheat the oven to 120-130 degrees C (248-266 degrees F)
- Place your sculpture on an oven tray and bake for 30 minutes
- Carefully remove from the oven and let it cool
We’d also suggest baking your polymer clay on a standard setting (not fan-forced). The reason for this is that the fan can cause the temperature to spike, making it harder to control the heat.
6. Don’t use a microwave
Putting polymer clay in a microwave won’t harden it properly and may cause parts of your project to melt, burn and smoke.
7. How long do I bake my polymer clay for?
Baking times may vary, but in general we’d recommend 30 minutes of baking for every 6mm of polymer clay thickness. It’s also a good idea to do a test run with some spare clay before you put your finished project in to bake. Here are a few examples to help guide you:
6mm thick: bake for 30 minutes
12mm thick: bake for 1 hour
18mm thick: 1.5 hours
More than 18mm thick: bake in multiple sessions (see tip 11 below)
8. Checking thickness
To follow the baking guidelines above, you’re going to need to figure out how thick your project is. To do this, take a pin and gently push it into your work until it hits the core (if you’ve packed your project). Put a mark on the pin where the clay finishes and measure it to find out how thick it is. You’ll then need to smooth the pin hole over before baking.
9. Pack larger sculptures to reduce clay thickness
If you’re working on a larger sculpture, you might need to pack it to reduce the thickness. This will make it easier to bake and also means you don’t need to use as much polymer clay. Some common materials used for packing include metal, aluminium, foil and masking tape. If you’d like some pointers, check out our video on sculpting a polymer clay beetle.
10. Let your polymer clay dry slowly
Once your clay is baked, we’d suggest turning the oven off and opening the door to allow your sculpture to cool slowly. This will help prevent cracking due to sudden temperature changes. Once it’s cooled to room temperature you can take it out and admire your handy work.
11. Baking polymer clay multiple times
If you’re working with a thick polymer clay sculpture, a good method is to bake it multiple times. We’d suggest doing this in stages by building up layers one at a time. For example, if you’re building a 24mm thick sculpture, you can use the following method:
- Build a 12mm thick layer and bake it for 1 hour
- Let it cool
- Build a second 12mm layer and re-bake for another hour
You can also reduce thickness by packing the inside of your sculpture using the method in tip 9 above.
12. Why is my polymer clay cracking after baking?
There are a couple of reasons your clay may crack after baking, but the good news is that we’ve got a few tips you can try.
Sometimes under-baking polymer clay can cause it to crack. The chances of this happening can be reduced by following the suggested baking times on the packaging or in tip 7 above.
If polymer clay is too close to the element in your oven it can heat up too quickly and result in cracking. Try to place your sculpture in a spot that will get a nice, even flow of heat and you should be able to avoid this issue.
Cooling too quickly
As we mentioned in tip 10, if polymer clay cools too quickly after baking it can crack. The simple solution is to leave it in the oven with the door open to let it slowly to room temperature.
Whether you’re creating jewellery or a sculpture, you’ll thank yourself for reading these quick polymer clay baking tips. If you want to show us how your project turned out, feel free to tag us on Instagram or Facebook using @montmarteart. We’d love to see it!