Conditioning Polymer Clay without Trapping Air Bubbles

Conditioning Polymer Clay

Air bubbles will show as lumps on your beads.. So be careful not to trap them in your clay:

Nothing is more frustrating to a bead maker than putting perfectly nice beads in the oven, only to take them out all covered in bumps and bubbles!

Those bubbles are caused by trapped air in your polymer clay. Most likely put there, by the way you conditioned your clay.

The biggest culprit for trapping air is folds. When you fold over your strip of clay and insert it in your pasta machine fold last, a little pocket of air gets trapped in the fold. If you keep doing this over and over, more and more air gets forced into the layers of clay.

Some of these air pockets you will see. You can pop those with your knife or a pin. But some bubbles, won’t surface until it is baking and those are the ones that can be a real pain!

So to minimize the air getting trapped in your clay while conditioning, you can do some of these things:

  • Tear the clay instead of folding. This avoids air being forced into the clay.
  • If you do fold the clay, put the fold into the rollers first. This allows the air to escape better.
  • Pop or cut any bubbles that do form, as soon as you see them, they may hide on you later.
  • Pull or stretch your sheet of clay to help release air.

So, do your best to avoid trapping air in the first place and you will have a lot less problems with lumpy, bumpy beads showing up in your oven!

Cindy Lietz SignaturePolymer Clay Tutor


  1. Cindy Lietz, 18 May, 2008

    Work with clay that is firm. Soft, sticky clay tends to trap more air bubbles.

    Cindy Lietz’s last blog post..How To Sand Polymer Clay Beads Using Drywall Sandpaper

  2. Mia E, 16 July, 2019

    Hi Cindy,
    Your tutorials are great, but I am still having slight problems with air bubbles and I have tried some of your techniques to avoid them from appearing.
    I use a pasta machine to roll out my slabs, and it seems to make bubbles. I sometimes put a tiny pin hole in the bubbles and re-role it but it leave small scrapes.
    Once I see that, I roll it again and the problem repeats!
    Would you have any suggestions?
    Thank you for your help Cindy!

  3. Cindy Lietz, 19 July, 2019

    Hi Mia, a great way to release air bubbles it to hold onto your sheet… one hand on each end… and pull slowly to stretch the clay. Also make sure that when you put your clay into the pasta machine, that the fold always goes into the rollers first. That way the air doesn’t get trapped in the layers. You can do a search for air bubbles, using the box at the top of this page and find information that will help you prevent air bubbles. Hope that helps!

  4. Cynister, 04 June, 2008

    I had been getting air bubble until I watched this tutorial. THANK YOU! It worked wonderfully.

  5. Cindy Lietz, 08 June, 2008

    I am glad this was helpful for you! I LOVE getting your comments Cynister! Thanks!

    Cindy Lietz’s last blog post..Color Mixing Polymer Clay – Leaf Green Recipe Ideas

  6. Brenda, 16 October, 2009

    I have been working with clay for about two months and find it very relaxing. I own a home daycare and need something like this to relax. I used to work with clay back in school and didn’t realize how much I missed it until I purchased some. I am glad that I have ran across your site.

  7. Cindy Lietz, 16 October, 2009

    Hi Brenda,

    Thanks so much for sharing your story. I agree about how polymer clay is a great way to relax. The link by my name goes to another story that Betsy shared about how polymer clay relaxation therapy has helped her through some difficult health issues in her life.

  8. peggie, 23 October, 2009

    i got a bubble on my first batch of jewelry pieces, one piece. i will be more careful to follow these instructions next time…….wonderful! thank you so much!

  9. Cindy Lietz, 23 October, 2009

    Congratulations on your first jewelry pieces Peggie. For more info about avoiding those nasty bubbles, follow the link by my name.

  10. weeziegee, 06 June, 2011

    Finally got a pasta machine for my clay. Doing great until my finished products had air bubbles! I’m hoping that your suggestions will take care of that problem; a lot of time and effort goes into this stuff, as you well know, as well as those things that can never be duplicated. So I’d rather not have this happen again.

  11. Erica D, 23 July, 2013

    Hi Cindy,

    I made a pendant this afternoon and I just noticed (after it was baked and sanded) that there is two tiny air bubbles in one area on the piece. This is very noticeable after it was sanded, the areas became lighter than the colour I was using. I wondered, could I paint over it to cover it up? And if so, what kind of paint would you suggest? And could I still use finish over top the paint as well?!?

    Or if you had any other tips, I’m open to suggestions :)

    Thanks so much!!

  12. Cindy Lietz, 24 July, 2013

    Hi Erica, Welcome! I know it can be frustrating when a flaw or tow can pop up in your pieces, but as you get going you will learn how to avoid things like bubbles so that you don’t have to try and fix them later.

    On this blog there is an amazing mount of information that will help you answer almost every question you may have when working with polymer. At the top of the page you will find a search box. Type words related to your problems like ‘bubbles’ or ‘paints’ and a list of articles and tutorials (some free and some paid) that will answer your questions quite quickly. You’ll also want to scan the comments below the posts, because the members here love to share their tips, tricks and challenges and you will also learn a ton from them as well.

    I hope you enjoy your journey here… Have fun!

  13. Cindy Lietz, 24 July, 2013

    Hi again Erica, just looking back on what I just wrote to you, I see I really didn’t answer your question very well. So I will try again… :)

    I would have to see your piece to know whether or not painting it would be your best solution to disguising the sanded bubbles. But since I can’t see it, I can say that yes you can paint your piece if you want to.

    Acrylic Paints work well on polymer clay, before or after they are baked. (Use that search box like I mentioned in the previous comment, to learn more about using acrylic paints on polymer clay.) You can also use products like Gilders Paste and antiquing mediums as well as a host of other things.

    I hope that answers your question a little better. Let me know if you need more help.

  14. Erica D, 24 July, 2013

    Hi Cindy

    Thanks so much!! Appreciate it!!
    (Love the beginners course btw) :D

  15. Loretta Baker, 20 May, 2014

    Hi! First, I LOVE everything you do to promote polymer clay. I have a question that I can’t find an answer for. When sanding a piece that has crevices, I tend to get the ‘dust’ stuck in them and I don’t know how to get it out. I’ve tried rinsing and brushing it. What would you do?

    Another question that I have is about conditioning and air bubbles. I’m pretty sure I am following all the advice out there for conditioning my clay. When I have just a plain color I tend to get lots of teeny tiny air pockets that turn whitish when I’m sanding. It looks really awful when I’m working with translucent. How do I get rid of those bubbles? I have researched this to death and I am super careful about how I put the clay through the pasta maker but there they are!?!!? Am I conditioning too much? Not enough? This has me pretty frustrated.

  16. Cindy Lietz, 22 May, 2014

    Hi Loretta, As far as getting the sanding crud out of crevices, a tooth brush and some soapy water works great.

    With the air in clay problem, there is quite a bit of info on the blog. Just type ‘air’ or ‘bubbles’ into the search box and you should find something.

    Also it sounds like your clay may be too soft and causing you more hassles than it should. Do a search for ‘leaching’ and that will help a great deal.

    Let me know if this solves the problems for you.

  17. Loretta Baker, 22 May, 2014

    Thank you so much for answering so soon! I will check out the info.


  18. Lisa S, 20 February, 2017

    I have been working with polymer clay for years… Never had an issue with air bubbles… Bought a pasta machine and now I have tons. I’m so frustrated that I want to cry!

  19. Cindy Lietz, 21 February, 2017

    Yeah, there are some tricks to conditioning clay where you are not trapping bubbles. Follow the tips I suggest and watch the other videos I have on the subject. A good tug on the sheet of clay will also help to release trapped air. Good luck!

  20. Doreen N, 05 January, 2015

    After reading your tutorials about how to avoid air bubbles using a pasta machine, and getting a Never Knead (saw your tutorial about it, ordered on, and I LOVE it), I don’t seem to get too many bubbles working with “original” lumps of clay. However, could you please do a tutorial on how to get the flat pieces and small pieces of clay that are left-over after cutting out a project, back into a lump for the next project, without getting bubbles into that? I can get them back into a bubble-free flat sheet using my pasta machine, but I can’t seem to get them into a lump ready to roll out for the next project. I poke as many as I can see, but I’d like to get fewer of them if possible.

  21. Cindy Lietz, 19 January, 2015

    Hi Doreen, there are a few tricks for avoiding trapping bubbles after you have created your original piece… I should do a video on it. One thing is to try not to put your scraps together with folds of air in it. Another is to pull on your flat sheets to pop the bubbles when you are rolling the sheets out. Using your NEVERknead will help. Just keep squishing those blocks of scrap… it will eventually push most of the air out of it. I will add your suggestion to the list.

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