Top 7 most common polymer clay mistakes to avoid

Working with polymer clayAvoid these seven rookie mistakes to create stunning creations without frustration.

Don’t do what I did.

When first starting with Polymer clay, it’s all too tempting to just rush out, get some Fimo or Super Sculpey and start creating only to see your project mess up.  That’s exactly what I did.

I thought I knew enough, it’s polymer clay after all! How difficult can it be! But as with everything in life, mistakes are waiting for the inexperienced. I made loads of errors, most of those here TBH, which resulted in ruined creations and left me disheartened. I nearly gave up on the medium after my first attempt.

So in this quick guide, I’ll explore seven of the most common mistakes to avoid when working with polymer clay so that you can get started on the right foot By being aware of these mistakes and taking steps to avoid them, you’ll be able to create beautiful and durable pieces that you can be proud of.

1. Don’t skip the conditioning process

One of the most common mistakes that people make when working with polymer clay is not conditioning it properly. Conditioning involves warming up the clay with your hands and then using a clay roller or pasta machine to roll the clay back and forth until it becomes soft, pliable, and consistent. Failing to condition the clay for long enough can result in a texture that’s too firm and difficult to work with, and can lead to, as Sculpey put it,  cracking or crumbling up of the clay during or after baking.

Additionally, air bubbles can easily creep into clay, especially when folding it. These air bubbles cause unsightly bumps and defects that emerge when it’s baked. The recommendation is to always properly condition the clay, and use a roller or pasta machine, to remove these air bubbles. If you fold the clay, always roll it from the folded end so air bubbles can escape.

So make sure to take the time to condition your polymer clay properly before starting any project. Not only will it result in better quality pieces, but it will also make the clay easier to work with, enabling more intricate and detailed designs.

2. Don’t use dirty tools

Another common mistake that will lead to disappointment is using dirty tools. Polymer clay is susceptible to dirt, dust, and even fingerprints, which may transfer to the clay and ruin your final piece. Before starting a new project, wash your hands and wipe down your tools with a damp cloth or wipe over with some IPA and ideally use separate tools for each colour of clay.  I also keep a spray bottle of this nearby to clean my tools as I work and in case I get any marks or fingerprints on my creations (see my guide to removing fingerprints if this has happened).

On the subject of tools, I’d also strongly recommend getting a thin blade. This is a long blade, that’s very sharp but also thin, which makes it easy to cut the clay into slices and also makes it easy to lift clay off the working area.

3. Don’t overbake your clay

It’s important to follow the manufacturer’s instructions when baking your polymer clay. Overbaking can cause the clay to become brittle and break easily. Equally, if the clay comes out of the oven with dark spots or worse, bubbling, it’s been burnt which as Jennifer Courington at Sculpy explains is when the oven ‘is too hot due to one or more temperature issues:’

Use an oven thermometer to ensure that your oven is at the correct temperature, and don’t leave the clay in the oven for too long. Just as importantly, make sure you pre-heat your oven before putting the clay in; otherwise, it won’t bake at the right temperature in the time available. To correct colouring issues due to burning, use 1000-grit sandpaper to remove the burnt area and expose the original colour underneath.

4. Using too much paint or glaze

When painting or glazing your polymer clay creations, less is more. Too much paint or glaze can obscure the details and make your piece look tacky. Instead, use thin coats and let each layer dry completely before adding another.

And on the subject of glazing, when it comes to painting polymer clay, it’s important to avoid using nail polish as a glaze, despite how tempting it may seem. Although some types of nail polish can be used on other materials, it’s not recommended for use on polymer clay. As demonstrated in a video by Creative Rachy, nail polish can eat away at and dissolve polymer clay over time, causing it to break down and lose its shape

Instead of using nail polish, some other glazes and sealers work well with polymer clay, such as Varathane, PYM II, and Future Floor Wax.

5. Don’t work in a cold environment

Polymer clay is more difficult to work with when it’s cold, so make sure to work in a warm environment. You can warm up the clay by holding it in your hands for a few minutes before you start working with it. If the room is particularly cold, consider using a space heater or heating pad to warm up your work area if necessary.

6. Not protecting your work area

Working with polymer clay can be messy, so it’s important to protect your work area from any accidental spills or stains and avoid contamination between clays. Cover your work surface with a plastic or silicone mat, and wear gloves to protect your hands from any dye or pigment that may transfer from the clay. Before starting, wipe down your work area with a lint-free cloth and some IPA to clean it of dust, dirt and grime.

7. Don’t lose heart too soon!

Working with polymer clay can be a journey of trial and error, and it’s okay to make mistakes and experience some setbacks along the way. The key is to stay determined and keep practising, by trying out new techniques, learning from others, and exploring your creativity and you’ll soon develop the skills you need to create beautiful polymer clay creations.


Working with polymer clay is a lot of fun, but it’s also easy to make mistakes. By following these tips, you can ensure that your polymer clay creations turn out beautifully.

What mistakes have you made with polymer clay? Let me know in a comment below and, if you found this quick guide useful, please share it with your friends and other polymer clay creators you know.




Founder of ModelRailwayEngineer, Andy Leaning

Andy is a lifelong modeler, writer, and founder of He has been building model railways, dioramas, and miniatures for over 20 years. His passion for model making and railways began when he was a child, building his first layout at the age of seven.
Andy’s particular passion is making scenery and structures in 4mm scale, which he sells commercially. He is particularly interested in modelling the railways of South West England during the late Victorian/early Edwardian era, although he also enjoys making sci-fi and fantasy figures and dioramas. His website has won several awards, and he is a member of MERG (Model Railway Electronics Group) and the 009 Society.
When not making models, Andy lives in Surrey with his wife and teenage son. Other interests include history, science fiction, photography, and programming. Read more about Andy.

Afflliate disclosure:The links on this page may take you to carefully selected businesses, such as Hornby, Amazon, eBay and Scale Model Scenery, where you can purchase the product under affiliate programmes. This means I receive a small commission on any orders placed although the price you pay does not change. You can read my full affiliate policy here. I also sell my my own ready to use, pre-made and painted buildings and terrain features. browse the range.

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