How to Properly Bake Polymer Clay

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How to Bake Polymer Clay Tutorial on KatersAcres Blog

All you have to do is search the internet for help on how to bake polymer clay.  You will see a lot of wrong and incorrect instructions on how to do this.  But let’s be honest: every artist does this differently and every artist has their own system that works for them.  What works for me, may not work for you.  And the biggest thing with polymer clay … the baking times are different for almost every brand of clay and oven.  Today I’m going to give you a few tips on how to bake polymer clay items at home in your own toaster oven.

Read Your Polymer Clay Package

Polymer Clay Blocks

The first step is the most important, you must read the instructions on your package!  Every brand of polymer clay is different and has different specifications.  Every single bar of clay will have different baking instructions on the package. Baking instructions vary per brand and per type of clay. What works for one brand and type of clay will not work for another brand and type of clay.

TIP: As a general rule of thumb it is always best to bake your clay for a longer amount of time than your package recommends but not a higher temperature than your package recommends to avoid scorching your clay. NEVER bake your clay at a lower temperature, this will do nothing to ensure that your clay is properly hardened.

Know Your Clay

Because every clay is different, you will also find that the same brand of clay can vary in baking times across colors.  What I mean by this is that many colors of clay (especially in the Premo! brand) will darken after baking; especially when baked at too high of a temperature.  And again, I can not stress this enough, follow the recommended time & temperatures for each package and brand of clay. Some clay colors will do much better to be covered when baking to prevent the colors from darkening.

TIP: Everything I bake in my home studio is baked ceramic tile-lined metal pan and covered with a metal baking pan. This keeps my colors as true as possible, even my reds (which darken) and whites (which yellow) when baking.

General Rule of Thumb

I mix my clays and brands all the time.  I mix Sculpey III, Fimo, or Super Sculpey with Premo! every day in my studio.  There’s no “magic formula” to finding what works for baking times as every oven, craft oven, and toaster oven is different.  As for me and all my sculptures, I bake all my pieces at 275 degrees for 60-90 minutes.  If my piece goes through several baking steps, I still bake my item at 275 degrees, but only for about 60 minutes for the first bake, just to “firm up” the clay.  Then I continue working on the piece and continue baking in 30-minute increments.  However, for the final bake (when my piece has had multiple bakes) I bake the piece for no less than an additional 90-120 minutes depending on its size.

A Few Tips for You

How to Keep Clay from Burning

How to Bake Polymer Clay - Use Foil to Keep Your Items from Burning on KatersAcres Blog

One of the most common problems with polymer clay is the burning of the piece.  (I have written another article on this here, feel free to read it too).  I have on several occasions in the past, burned my sculpture … and it has not made me happy.  How and why did that happen? Because I let it in too long, or it was too close to the side walls/top of the oven, and portions on the sculpture burned.  To keep this from happening, use foil sheets (or foil pans) to cover your work.  These are the foil sheets that I have in my studio.  You can use them to cover most objects or attach two sheets together to cover a large object.  They can also be reused hundreds of times.  I still have one sheet that I reuse over and over and over again, it’s about a year old now.  This one box should last you at least a year, if not longer.  In addition and as a side note, I cover everything!  There is nothing that goes into my polymer clay oven that isn’t covered.  I work too long and too hard on my pieces to have accidental burning!

Stabilize Your Unpredictable Toaster Oven

How to Bake Polymer Clay - Oven Tips by KatersAcres

If you use a toaster oven, the oven is most likely highly unstable and prone to spikes in temperature.  When this happens, it will cause your polymer clay piece to crack or burn.  And this is sad, very sad.  There’s an easy way to prevent this from happening.  At the left is a picture of my toaster oven.  Take a look at what I’ve done to the inside of my oven, not only does it have an oven thermometer inside, but you will also see several varying sizes of ceramic tiles.  I purchased ceramic tiles at my local hardware store and bought them to fit the inside of my oven. This helps to act as an insulator to keep the oven at a more stable temperature.  I also have a 12×12 ceramic tile block (also from my local hardware store) sitting on the top vent of my oven, again to help insulate and keep the temperature stable.

Please take note, this is not my idea to use ceramic tiles in your oven.  I have seen this on several websites, blogs, and even floating around Pinterest.  I have no idea where this idea originated or who to give credit to, but, alas … it is not me.  But thank you for thinking that I’m actually that smart!

Thank you for being a part of the Kater’s Acres Family, Sculpting Blessings,


35 thoughts on “How to Properly Bake Polymer Clay

  1. […] Once cooled, pieces can be sanded, painted, and sealed. With proper baking and curing, polymer clay sculptures will maintain their shape and color vibrancy for years to come. Be sure to frequently wash hands after handling uncured clay. Cite: […]

  2. Hello, question 1- is the ceramic tile glazed or unfinished? question 2- I have seen pieces that have some really delicate details can the clay be painted after the firings but before clear coat seal? Question 3- I have also seen pieces that have jewels and crystals inlaid which is better to make a indentation bake then glue jewels or can you inlay the gems and bake the clay with them in the clay?
    Thank you

    1. Thanks for asking Marci.
      1) Glazed ceramic tile, no texture.
      2) Yes, they can be painted with either (or both) acrylic or oil paints.
      3) I place my crystals before baking and use Bake & Bond or similar to help adhesion if it won’t obstruct the stone’s sparkle. Or you can use clay and decorate around the placed stone to help it stay in place post bake.

  3. Can you tell me if a Sculpey mold can be used for casting brass?

    1. Do you mean the Sculpey Mold Maker clay or the mold used to pour hot metal into?

  4. I’m just getting started and I wanted to know how long to bake something if it is 2 or 3 inches high? Like an elephant, dog, cat etc… I also bought sculpey clay and wonder if I should return it and buy more expensive?

    1. Hi Wanda, Nothing (and I do me NOTHING) in my studio bakes less than 45 minutes. For something like that I would bake it for at least 60 minutes. I would go with Premo clay, I think you’ll like your results better.

      1. Thanks Katie for your response. I have already made some mistakes and have learned a few things. Forgot to reinforce a doll head to the body with a toothpick and it keeps falling off. I made a dog from sculpey clay and the tail broke off. I baked both things for over 60 minutes at 275* so not sure what happened with the dog tail. Should the pieces be flexible after baking or rock hard? Thanks for your help, I am planning on doing some projects with my grand kids and would hate for them to break apart.

        1. Hi Wanda, the flexibility question is a tough one. Clay is a bit flexible by nature, but it should be hard as well. If the clay is thin, it should be strong and flexible. If the clay is thick it should be tough and rigid. I hope that helps a little. If the clay is brittle, it likely did not bake long enough and hot enough. Make sure you are using an oven thermometer and double check your oven is getting to at least 275 degrees. I bake NOTHING in my studio less than 45 minutes. Often things bake for about 60-90 minutes in my studio.

  5. Do you have a regular oven or the craft and clay polymer oven, does it mater

    1. You can use a dedicated craft oven, a toaster oven or your regular oven. It does not matter. It just needs to be at a constant and steady temperature; that is more important.

  6. Any ideas in WHY my clay is MELTING instead of hardening??!!

    1. Polymer clay should NOT melt, ever. Are you sure it’s polymer clay and not plastilina? Plastilina is right next to polymer clay in craft stores and is much cheaper. It is often confused for polymer clay.

  7. Thank you so much for your great baking tips! It’s such a disappointment to burn something you have worked hard on. Lots of good info here, I enjoy your site.

    1. You’re welcome. I’m glad you have found them useful.

  8. Would the Reynolds brand Wrapper foil sheets be OK to use on clay projects? Also, I have always baked my clay pieces on a tile placed on the center rack of my oven. Seems to work great, but at times the piece seems to slightly stick to the tile. Any suggestion? Really love your site and have learned so much from it. Thanks

    1. Hi Dorothy! Thanks for visiting. You can use the wrapper foil sheets to COVER your clay, but do not set your clay on it to bake. In regard to your piece sticking to the tile, place a piece of printer paper on TOP of the tile, then place your project on top of the paper. The paper will not burn and your project will not stick. I hope this helps!

  9. Never thought of the tiles in the toaster oven! Buying a few tomorrow. I just started working with polymer clay and hopefully this will help!

  10. I have no idea clay can be baked. I thought clay is for the children to play. But now with help of your baking tips, I’ll try this.

    1. Please check your clay Charlotte. Not all clays can be baked. This article was written for polymer clay. Polymer clay is different than air-dry clay or paper clay.

  11. Hi! I love your tips and tutes!!! My question is regarding the ceramic tiles. You mentioned that you put one on top
    …I was wondering if it on the top rack inside the oven on the top of the outside of the oven? Thanks so much for sharing your time and talents! 🙂

    1. Hi there! I have a marble tile on the TOP (outside) of my toaster oven. It covers the vent to keep heat from escaping too fast and cooling the oven too quickly.

  12. Here’s a weird question. I had not heard about the temp is better higher rather than lower so after crisping a few pieces have been cooking at a lower than normal temp for double the recommended time (like a good Texas brisket is cooked ). Thick pieces are coming out fine but thin, delicate are crumbling so easily. So here’s my question, can I rebake pieces for your recommended 45 minutes at clay recommended temp or are they lost cause?

    1. Hi Jenifer! Thanks for asking. Polymer clay MUST be baked no LESS than the recommended temperature or it will be crumbly and brittle. Most brands of polymer clay are super strong after baking, when baked correctly. Your pieces could have been burning at the higher (recommended) temperature because they are 1) too close to the heating elements 2) your oven is spiking in temperature 3) you are mixing brands of clay that bake at substantially less temperature than others. I hope these tips help! Thanks for stopping by.

  13. Terrific article. I appreciate your tip on multiple baking times. I wasn’t doing the 10 mins the first time, because I don’t often know that I’m going to be baking a 2nd or 3rd time in the beginning. I was nervous about doing a longer bake in the end after having baked for 30 minutes the 1st time, but to assure what was added on in the end, still needed to. I’m always careful how items are covered, no problems thus far.

  14. I am new at working with polymer clay and I’m not sure if anyone has already asked this, but is it possible to make paper weights with polymer clay? If so, does the clay have to be flat or can it be in a large ball (about the size of a cupcake or softball)? Please let me know if this is possible and if I would need to change anything with the baking temperature or time. Thank you.

    1. The possibilities with polymer clay are limitless. You can absolutely make paperweights. I would make an armature first. Then cover the armature with clay, bake, & you’re finished!

  15. May I ask a question here? I’m still very new to polymer clay and loving every minute but I still don’t seem to be able to get my baking consistently right. Because I find it hard to get a consistent temperature and was afraid of going too hot, I started out baking everything at probably a couple of degrees lower than ideal. Everything came out looking fine but I was afraid I might have problems down the line with brittleness so I asked a professional (I won’t name her) and she said it was better to bake at too high a temperature than too low and that my work wouldn’t burn as long as it was covered. She also said that she bakes for several hours regardless of size. Yesterday I tried to bake a piece that was about two inches at its thickest point. I baked it at around 264 degrees for 2.5 hours but it sill came out burnt and discoloured. Please can someone tell me what I am doing so wrong? Might it have made a difference that I checked the piece several times during baking (the burning happened at some time during the last hour and everything seemed okay up to that point)? I baked it on a ceramic tile with several pieces of paper under it and enclosed it in a disposable tin baking dish with another on top, the two of them held together with bulldog clips. Please can someone help as I am getting desperate! Thank you for reading.

    1. Lyn – It sounds to me like your clay is too close to the heating element. The person who told you that it is better to bake at too high than low is exactly right. If you bake clay too low is it brittle and will not have the strength it is supposed to have. The only thing that would cause this kind of scorching is the clay being too close to the heating elements. You should have no less that 1/2″ clearance from each heating element. Additionally, covering your item would also help.

  16. Thankyou! Was looking for baking tips that actually stated temps in F• or C•

  17. Thanks so much for the tips. Until now I was afraid to bake my pieces multiple times. I can’t wait to try it out.

  18. Great tips Katie, I wasn’t aware that covering with foil helps and neither knew about the tile tip..Thank You !!
    Yesterday night, I worked on two pieces for about 4 hours..from 9:30pm to 1:30 am..and burnt them in 10 mins:(
    I had accidentally turned the temperature setting to 400F while moving the oven ! my clay pieces stood no chance against that! Its painful when it happens .So making sure our oven settings haven’t accidentally changed since you last used before baking the clay is also a good idea 🙂

  19. I always cover with foil, too, since I have a rather small oven, but I did not know about the ceramic tile tip–thanks!

    1. You are welcome! It’s been the single best thing that I have done to help control the heat and fluctuations of temperature.

  20. Great baking tips here Katie, thanks for sharing!

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