Friday, April 5, 2013

Polymer Clay 101 - Chapter 1: Think Wax!

I have decided to post a series of basic information in addition to my regular posts.

This is the beginning of a monthly (hopefully!) series of posts that are intended to give you my experience with polymer clay and my observations of this unusual medium, from the bottom up. I would like to help new clayers to understand the medium, to become familiar with its quirks, so they can concentrate on creating, not getting bogged down because of "failures" due to technical problems. I'm a firm believer in there being no mistakes in creative endeavors, but it's heartbreaking and frustrating to have your efforts end up broken, burnt, or otherwise useless. This is meant solely to offer my lessons learned, observations made and conclusions drawn during my 24 years' progress as a polymer clay artist.

1: I don't think of polymer clay as "clay". It does not act like earthen clay at all. I have come to think of it in terms of "wax" as it behaves similarly to wax, and this reminder helps me when I'm working absentmindedly and not getting the results I would like. Wax softens with heat. So does polymer clay. I often pack the clay into my clothing before starting a day in the studio, and this warms up the clay safely. That does not mean warming up the clay results in "conditioned" clay - it just helps with the conditioning process. The clay still needs to be thoroughly mixed to redistribute component chemicals and yield a good, strong, final product.

Earthen clay takes an impression quite easily. Wax does not, neither does polymer clay, especially if it is not warm, soft and pliable, so there are several things you can do to help it warm up. Friction transfers kinetic energy to the clay, thus warming it a bit as you roll vigorously across the surface with your acrylic rod. Putting hard pressure does not do much to help. Think of putting pressure on a wax candle - see? Warming up your instruments (pasta machine, tile or glass work surface, etc. will help, mainly because these items tend to be cooler to the touch and suck the heat out of the clay as you work on it! So warming these up with a hairdryer (or a heating pad) before you start working, really helps.

Speed also impacts on the results. Unless your polymer clay is very warm, soft and pliable, you need to affect it slowly in order to achieve good results. For example, the images below show fairly softened clay run through the pasta machine rolling slowly (#1 - on the left) vs rolling quickly (#2 - on the right):
please click on image for larger picture
These pieces were conditioned, the same size, rolled on the same setting on the same pasta machine, using the same rubber stamp. The difference is due to the speed of rolling. Rolling slowly allows the clay to "yield" to the pressure and conform to the stamp shapes whereas rolling quickly causes a wave of clay to move ahead and the impressions are not as deep and are quite distorted.

Thinking of polymer clay as similar to wax helps to understand other things that happen. For example, translucent clay has a property known as plaquing - forming small, flat, roundish discs below the surface when baked. This is a wonderful quality when you want to mimic jade or some other stones, however, it can be a nuisance when you don't want it. The reasons for this occurrence are not fully understood, although some feel it may be moisture from your hands that contributes to it happening. In watching what happens when I run translucent clay through the pasta machine, it became evident that rolling too quickly tended to trap minute amounts of air in the clay, which looked like small, whitish striations barely visible below the surface. Rolling slowly, this did not happen. I feel that this is another situation where rolling quickly doesn't allow the clay to conform to surface differences, whereas rolling slowly does, and it gives the clay time to fill in depressions and air does not get trapped. This seems to be particularly important in translucent clay which, for some reason, seems more waxy than pigmented clay.

'nuff said! Please feel free to leave feedback.


  1. Hi Vickie,
    Nice article. That comparison to wax is very good. I never put my clay and texture sheet through the pasta machine because of just the things you mentioned. Thanks for the lesson.
    I posted your site on Polymer Clay Central. I'm sure they will enjoy it as much as I do.
    Take care, Jay

    1. Hi Jay,
      That was really nice of you! Thank you very much! I've had a ton of hits from the forum today, thanks to you. Hopefully some will find it useful.

      Warm regards, Vickie

  2. Every time I run my clay through the pasta machine it comes out with black marks all over the clay. Help! I've cleaned and cleaned this pasta machine and still get these marks. Has this ever happened to you?

    1. Hi Pam, yes, I know exactly what you mean. This has to do with the metal of the rollers. I believe they were a type of steel originally and it may be a matter of a combination of machine oil and the roller metal creating the problem.

      I now have a machine that never puts the dark splotches in my clay. It is the Atlas Marcato 180 that I bought from Mona Kissel ( with the custom scraper blades. The rollers on this machine have a very fine texture and, I believe, are aluminum.

      The problem with most new pasta machines is that they now use plastic scraper blades and these don't last and don't do the job with the heavy duty work I put my machines through. Mona and her husband replace the blades that come with the Atlas with ones custom designed to unscrew easily for cleaning so you don't have to disassemble half your machine to clean it.

      The only problem I have now is that my machine squeaks from time to time and that can be a bit irksome. Aside from that, I'm very happy with this thing. No more dark streaks!

      I still hang on to a couple of really old Italian 4" machines in case of emergency. These things just don't quit, but the width is so narrow that it is cumbersome to work with daily.

      All that having been said, the dark streaks are annoying but I never found them to be a big problem as far as affecting the final colour of my clay. However, I tend to not really worry about schmutz or contaminants in my clay unless they affect the final finish.

      Thanks for leaving your question. Hope this helps a bit.

  3. I appreciate this information! I haven't done a lot of work with polymer clay recently, but find it fascinating and want to play with it a bit again. Thank you!

    1. Hi Carmen,
      Thank you for leaving a comment. It really helps me stay motivated, knowing that the information can be useful to some. I hope you get back at the clay again soon. It is a wonderful medium to explore.

  4. A wonderful article and so informative. I was used to working with clay and became frustrated with polymer. Your tips and suggestion to view the clay as wax has given me a new view and desire to try again. Thank you.

    1. Hi,
      Thanks for leaving a comment. I'm glad you're going to give it a go again. Polymer is not just an amazingly versatile medium, I find it also encourages my creativity. I know how frustrating it can be until you fully understand it, but when you do get the chemistry and the physics of it, it's great to work with. I find I rarely have technical disasters any more so I can really push it and experiment. I wish you success!

  5. Thank you for sharing this info. As a newbie I soak all info before starting anything and this most helpful!

    1. Hi Catherine,
      I'm glad you found the blog and found the information helpful. That's a reward in itself as far as I'm concerned. There is a lot of wonderful information in cyberspace but don't forget to take time to "do", not just read. You'll learn so much in the doing. Have fun. Vickie