Sculpting polymer clay characters should be a relaxing endeavor, so there's nothing more frustrating than spending hours on your model just to have it burned, or worse, cracked after baking. Not only can the type of clay you use determine if you’ll have issues, but the type of oven and baking process all affect the outcome of your character model. If you’re just starting to work with polymer clay, it can feel overwhelming when you don’t know why something went wrong or how to repair your sculpt. If this has happened to you, don't give up! In this tutorial, we’ll go through all the pitfalls that can arise when baking polymer clay characters with simple steps on how to fix each issue. For demo purposes, I sculpted an English football fan cheering at his local pub. (The club he's rooting for is Brighton & Hove Albion in case you're wondering!)

DUST AND LINT
Why it Happens
Dust and lint are the thorns in every polymer clay artist's side. If you have pets, well, you get it. Little hairs and fibers are everywhere and even the best prevention methods won't stop it completely from getting into the clay while you sculpt. But there are ways to make it less annoying (and visible).

Preventing and Removing Dust and Lint Before Baking
Wear white cotton or polyester. If possible, avoid fuzzy sweaters.
Make sure your work surface is clean and wiped down.
Wash your hands and roll them with a lint roller. I keep one on my desk to roll over my palms before I start sculpting, then wipe any residue with a baby wipe.
If possible, keep your nails clean and short to avoid dirt and dust sneaking in while you sculpt.
Baby wipes are helpful to remove lint from raw clay, but sometimes it can also add more lint, so just be careful.
Tweezers can work sometimes, but they don't always have enough force to pull fibers out of clay. Sometimes using your fingers to pull out lint or animal hair works better.
Brushing alcohol on the clay will help pick up dust.
My most preferred method is using a craft or X-acto knife to remove stubborn lint.
Removing Dust and Lint After Baking
Once your piece is baked, you might see pieces of lint that you swear were not there before you put it in the oven. You can try using a cotton swab dipped in acetone or nail polish remover to brush onto the clay. Acetone eats into the clay which makes the lint easier to remove, just be careful not to use too much. If you do use acetone, you may get cloudy white marks on the clay. Rub a tiny bit of petroleum jelly or baby oil on it to remove them.
Worst case, if the lint is deeply embedded in a highly visible spot that will not be painted over, you may want to use your craft knife to gouge it out, then add oven-bake clay adhesive, smooth raw clay over it and re-bake. Or if it works for your piece, skip the gouging and simply add some raw clay on top of the spot to cover it up and re-bake.

MOONIES
Why they Happen
What are those weird white blisters under my doll's skin?? Those, dear friend, are moonies. Moonies look like half-moon white blisters that appear under the surface of clay after it's baked. They show up in certain clays when they aren't conditioned enough and air gets trapped in the clay during baking, causing a bubble under the surface. If you plan to paint your piece, they really aren’t a problem, but if the clay is supposed to be your character’s skin, then it could be a big problem.


Preventing Moonies in Polymer Clay
The type of clay you use is the best way to prevent moonies in the first place. The worst offender in my experience is Super Sculpey Original (not the gray series, the beige one). You can condition this clay as much as possible, but the moonies will appear anyway. So as a rule, I never use Super Sculpey Original for skin, only the body or clothing which would be painted later. For smooth, consistent looking skin sans-moonies, I personally think ProSculpt is one of the best clays. It’s only slightly more expensive and well worth it. It’s got a wonderful texture - firm enough without being crumbly, but not too soft. And so far, I’ve never had moonie problems. Another great clay is Sculpey Living Doll. I use this all the time, it's very similar to ProSculpt.
How to Fix
Moonies can be tricky to fix, especially because they don’t tend to show up one at a time, they appear in groups and go everywhere. If they’re all over your piece, you will have to either paint over it or chuck it and use a different clay that's less susceptible to moonies like ProSculpt or Sculpey Living Doll. But in the off chance you only have a few, you can try gouging out the moonie with your craft knife, then add raw clay over it and smooth with clay softener. Once you re-bake it, it should blend in nicely. If you notice discoloration, it might not be fully cured and you’ll want to bake for another 10 minutes, letting it completely cool down for a couple hours before taking it out. If necessary, sand your repair down to blend any uneven or raised edges into the rest of your piece. I'm choosing to leave the moonies in our model since they appeared on his clothing and we'll be painting that.
BURNS
Why they happen
Burns can happen for a number of reasons, like when your piece is too close to the heating element of your stove. You'll want to use the correct support material in the oven and ensure your model is covered fully. If your character is face up in a toaster or kitchen oven with no cover, chances are you will end up with burns on delicate areas like the face or feet. Check if your character is too big for your convection or toaster oven. You may need to bake it in your kitchen oven. If your character has parts that are too close to the heating element, try moving the baking tray down to the bottom level.



Preventing Burns in Polymer Clay
There are four methods that can help you prevent polymer clay burns:
Use an oven thermometer. If you're using a non-convection kitchen or toaster oven, you will want to use an oven thermometer as typical ovens are notorious for uneven heating. I'd recommend what I use - a dedicated digital convection toaster oven. Convection ovens circulate heat evenly which helps prevent burns.
Line your cookie sheet or oven-safe glass container with parchment paper, Poly-fill or cotton batting to support your model. Parchment paper won't leave shiny spots on the bottom of the clay the way aluminum foil, glass or metal trays do. Cotton batting or Poly-fill can be found at local craft or fabric stores and is helpful for when your model is too tall or won't stand on its own and needs to lie horizontally. They both provide some nice, cushioned support. Just beware, there will likely be some stringy bits clinging to your model that leave impressions in your clay, but they can be lightly sanded off. TIP: Sometimes you need a taller support for a certain part or parts of your model. Simply bunch up some aluminum foil and place a thin layer of cotton batting over it to avoid shiny spots.
Always cover your model. Make a tent of aluminum foil to arc over it so it doesn’t touch the character. This has worked great for my pieces, and I haven’t had any burns. Some people put Poly-fill on the hands or feet, but as mentioned, Poly-fill is stringy and it can leave impressions in your clay which will need to be sanded. But a decent aluminum sheet tent over the entire character should suffice, especially if you have a convection oven where the heat is circulating.
Bake at a lower temperature for a longer amount of time. My particular oven is digital and for some reason doesn't allow temperature increments of 5°, therefore I can only do 270°F or 280°F degrees, not the recommended 275°F. So, for all my bakes, I set my oven to 270°F for 20-25 minutes per 1/4" thickness. This works perfect for me. Even if you set it to a lower degree like 265 and bake a bit longer, it will not cause your model any harm. Some artists swear this method makes the clay stronger.
How to Fix
If you do get burns, there are a few options.
Sand down and add raw clay. First, only sand in a well-ventilated area and wear a disposable dust mask or N95 mask to prevent breathing in polymer. Next, take a wet/dry sandpaper sheet (400 grit) or sponge and dip it in water. Now carefully sand the initial burned layers. You don't need to sand deeply because you're going to cover the area with raw clay. (TIP: If you're dry sanding, try it over an electric nail dust collector. Used for polymer and acrylic nail filing, these fantastic little machines vacuum up dust into a filter for easy disposal.) Add your raw clay to the areas and smooth out the edges with baby oil or clay softener. Cover and re-bake.
I sanded the burned area over a nail dust collector, which sucks in the dust as you sand into a reusable filter. (I also use this when removing my gel nails at home, so it's dual purpose!) For spot burns, use an X-acto or craft knife. Be as gentle as possible here because putting too much force on your knife could cause a crack elsewhere. Once you’ve removed the burned clay, brush on oven bake clay adhesive and press on your raw clay. Re-sculpt, cover and bake.
Paint over it. It's usually better to try to repair the clay before painting, but if you were, for example, going to paint your model black to start with, you wouldn't be in bad shape. Just sand it down a little to get rid of shine and help the paint stick. You can also try priming the model with layers of gray or white paint to cover the burn, then adding your colors on top.
If all else fails, say goodbye. If the burns are too many or it’s just not salvageable, you may sadly have to salute it and chuck it away. But if you follow the four preventative methods, bad burns should become a thing of the past!
CRACKS AND BREAKS

Why they Happen
The reasons cracks and breaks happen are varied. Like a bone, a crack can appear as a fracture in the clay, while a full break is just as bad as it sounds. The arm or leg of your character snaps in two, or the neck snaps apart from the head. It is hysterically frustrating. (In fact, I suggest laughing for a good 5 minutes to prevent uncontrollable crying.)
Cracks and breaks can happen if the piece wasn’t baked long enough or was taken out of the oven too early before it cooled down completely. Not waiting for my model to cool completely was my biggest mistake when I first started out with polymer clay.

I used to think as soon as that oven timer rang, my little character was done and ready for removal. I didn’t understand it needed to cool down for a couple hours in the oven, so I kept repeating the mistake and consequently, kept getting cracks and full breaks. (Instead of figuring out the answer though, I quit polymer clay for two decades. Don’t quit your daydream, kids!) Now, full disclosure - sometimes I have had amazing luck with pieces that didn't crack after I removed them soon after they were done. Case in point - the Brighton fan model we're using! (I even tried to get his arms to crack for this blog by moving them around after removing him from the oven. Didn't happen. Any other model that I didn't WANT to crack, absolutely would have - so it's totally my luck. 🤦♀️Consequently I made the gray scarves for demo instead.) My only guess it survived is because my convection oven distributes heat pretty evenly, so maybe that helped (?). But if you've spent hours sculpting a character, I really wouldn't risk taking it out right away.
Preventing Cracks and Breaks in Polymer Clay
Check for bubbles. Inspect your model for any visible air bubbles in your clay and burst them with a needle tool, then smooth them out before baking.
Cushion parts that need support. Polymer clay softens as it heats up and if there is any weight or gravity on certain parts, they can droop, potentially causing cracks to appear later. Ball up aluminum foil and mold it into the shape you need, then place a thin layer of cotton batting on top for your model to rest on.
Practice good timing. Check the clay’s package directions to make sure you bake your model according to specifications for the right amount of time. Usually, it’s 15 minutes per quarter inch at 275 degrees Fahrenheit. Bake in layers if your model has contrasting areas of thin and thick. You can also bake it at a lower temperature for a longer period of time. Polymer clay can withstand multiple bakes.
Let your model cool down in the oven completely. At the very least anywhere from 1-3 hours, depending on the size of your model.
Keep the room temperature consistent. If you have a ‘smart’ thermostat that, I don’t know, tends to always throw your house into Eco Mode (Thanks, G***le!) or you live in an area with extreme cold or hot temperatures, make sure to set your thermostat appropriately to retain an even temperature throughout your bake and while it’s cooling down. Sudden changes in temperature could cause cracking.
How to Fix Cracks
Depending on where the crack occurred on your character, there are a couple ways to fix it.
Plastic wood filler or epoxy putty. If you can’t or don’t want to re-bake your piece, use a plastic wood filler or epoxy putty which is stronger than filler (both available at hardware or craft stores). They take about 24-36 hours to cure, but they are sandable and paintable.
Oven bake clay adhesive and raw clay. If the crack occurred on the skin of your character (and you’re not planning to paint the clay), then the above options probably won’t work. In this case, your best option is, you guessed it, fill the crack with oven bake clay adhesive and smooth a thin layer of raw polymer clay over the crack. Brush some baby oil or clay softener over the raw clay to remove fingerprints and smooth out the edges. Re-bake and you should be all set. Remember, if the raw clay is still not the same color as the baked clay after your repair bake, it needs more time in the oven to cure.

Repairing Full Breaks
Like cracks, there are a few ways to fix full breaks.
5-minute quick set epoxy glue and plastic wood filler. If you will be painting over where the break occurred and you don’t want to re-bake, try 5-minute quick set epoxy glue to create a strong bond between the two pieces. You'll probably still see the break line though, so I’d recommend using a small paint palette tool to fill in any gaps with plastic wood filler. Remove the excess with a damp paper towel and let it dry for a few hours before sanding and painting.
Oven bake clay adhesive and raw clay. If you do want to re-bake, it's the same method as fixing cracks. Brush on your clay adhesive and sandwich the raw clay between the two pieces. Press them together lightly, removing or smoothing any excess clay that squeezes out. You want to remove as much air as possible. Then apply raw clay over the break and carefully sculpt and smooth out. Remove as much excess as you can, but if it's not completely flat, it's ok because you can sand it later to blend it in.


And without further ado...here he is - our Brighton fan is fully repaired and ready for paint!

YOU'RE NOW READY TO REPAIR YOUR POLYMER CLAY SCULPTS
Thanks so much for joining me in this polymer clay tutorial! I hope it keeps you from making common mistakes that can lead to damaged (or worse, abandoned) models. And in case something unfortunate does happen to your hard work, you'll be prepared to fix it and get it looking good as new. Remember, making characters with polymer clay takes practice and experience, so be patient with yourself. We'll continue next steps on our Brighton fan character model with February's tutorial, Polymer Clay Character Painting Techniques. If you have any questions or want to share your own experiences or tips, please feel free to comment below. Till the next tutorial, sculpt with character!
Liz Morris
Artist and Founder
Peppermint Rose Productions
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