The Polymer Clay Test To The Latest, Pardo Art Clay, Fimo Classic, Premo Sculpey And Cernit Testing Begin At 140ºC/150ºC For 30 Minutes (Preheat oven for 15 minutes) Test One

On 20-Dec-2011, at 2:01 AM, Kristy wrote:

Hi Garie,
I wrote you a while back about the strength of p.clay since the formulas have changed. I've had to restructure my business of 20 years because none of the clays are strong. Cernit was always my clay of choice.
Have you found out anything new? I'm going to have to switch to PMC if the quality of the polymer clay isn't improved. I'm having to make intricate armatures for everything and use superglue as the clay doesn't even adhere to itself anymore!..not to mention all the cracks &, the Cernit isn't pretty anymore...the colors are more opaque and muted. It used to have such rich that is gone too.
I wondered if you had heard anything before I invest in a kiln and all that.
It reads on your site that Cernit is the strongest...but, alas, this does not hold true any more.
Thank you for your time,

On 29-Dec-2011, at 03:33 PM, Garie wrote:

Hi, Sorry I didn't reply to you earlier, I have to update some of my experiments, to make sure that the clay you have mention is still strong, flexible with good adhesion.
The Cernit clay is still a good quality polymer clay, the change of formulation to polymer clay require me to update the clay from time to time.

Actually, all the quality polymer clay are strong, flexible with good adhesion, it depend on what you are creating, it also depends on the conditioning of the clay.
Polymer clay cannot be compare to PMC (Precious Metal Clay), the chemical composition is different and the curing temperature are also different, The curing temperature for different PC starts from 110º C, where else, PMC needs to dry before firing, depending on the type of PMC, temperature for firing/curing in the kiln range from 900º C -1000º C.You can used both to enhance each other, but you can't compared them, as the composition and material are different.
Polymer clay, composed of polyvinyl chloride, plasticizer, fillers, contain epoxidized soybean oil and colorants, baking temperature from 110º C and 130º C to harden the clay.
PMC contains fine metal particles, gold, silver, copper or platinum, mixed with organic binder, firing from 900º C will bind the mixture into a solid metallic form. PMC, can also create art form with pottery clay at the firing temperature of 900º C, which the clay particles will fused or cement themselves into a very hard material.
Back to polymer clay, when you are creating things with polymer clay you don't intentionally exert pounds of force just to touch, feel or hold the clay creation, it will definitely break your clay project 
It will be good if you want to switch to PMC as the jewelry items or accessories will be more permanent, but you will need to paint the thing that you are creating.

Another option will be colored epoxy clay, it will be a good clay and very strong, but not flexible, adhesion start on the begining of your clay work before it is cured within 2.0 hours. I think more colors are in production. Look for A+B Colored Epoxy with 2.0 hour setting time that might be the best solution in what you are creating as compared to the expensive PMC Clay.

You can view my latest test at,

Happy Holidays!


Pardo Art Clay Pardo Art Clay is crumpy Conditioning is messy Taking more than 5 minutes to condition Condition above 5 minutes still unable to blend the clay properly Closer veiw of the clay Finger kneading is required to condition Pardo Art Clay Fimo Classic Fimo is also crumpy Although the Fimo Classic is Crumpy, it is easier to condition Conditioning within 3 minutes will blend the clay The above shows the smoothness of the clay after conditioning Premo Sculpey Premo Sculpey easy to condition, no crumps Less than a minute and it blends easily Close up view of the clay after conditioning Cernit Cernit clay is also very easy to condition Conditioning the clay will soften the clay quickly If the hands is too warm, will make the clay too soft and difficult to form or shape Test tile
Strength test on the various types of clay
Test Flexiblity At 1.5mm Thickness Test on flexiblity of the various types of clay Pardo Art Clay firm and flexible Fimo Classic Clay Flexible Premo Sculpey Clay very flexible Cernit Clay flexible firm and flexible Adhesion Test Crossed clay adhesion test Prardo takes 41 times scissor action to seperate the clay Fimo Classic takes 32 times scissor action to seperate the clay Premo takes 13 times scissor action to seperate the clay Cernit takes 17 times scissor action to seperate the clay Strength Test Tension test Chart For Temperature Test At 140º C/150ºC For 30 Minutes







 Flexing and bending 100 tmes without breaking


Scissor action on crossed polymer clay 41 times to seperate

 10 pounds and still holding

   No Change In Color


 Flexing and bending 100 tmes without breaking


Scissor action on crossed polymer clay 32 times to seperate

 10 pounds and still holding

 No Change In Color


 Flexing and bending 100 tmes without breaking


Scissor action on crossed polymer clay 13 times to seperate

 Broke at 8 pounds

 No Change In Color


 Flexing and bending 100 tmes without breaking


Scissor action on crossed polymer clay 17 times to seperate

 10 pounds and still holding

 No Change In Color
Clay Test Two Test Date 25 December 2011

December 31, 2011 AM 12:05:57 GMT+08:00

Thank you, Garie  :O) 
I'm looking into your Epoxy clay suggestion....thank you very much for the idea.
 I don't need flexibility. Just reliable strength. I think part of the problem is oven temp and duration of baking time. The original Cernit wan't so heat-sensitive and was much stronger and prettier. You have to get the new Cernit to a certain temp for 30 minutes for strength...but if it goes over any little bit in temp or time you end up with awful fissures all over the surface. Different colors are more sensitive than others. It's all very frustrating, especially when having to bake bigger things. I use mostly white Cernit & it seems to be the most heat sensitive....and it's crumbly and hard to's nothing like the original white used to be. Adding translucent to it helps.
I had much different results in my baking tests than you did. We are probably working with different batches of clay. When the Cernit changes were going on each new experimental batch would be released to the public about every 6 months in the same packaging.....they didn't use new packaging with the new cooler oven temps listed on them. Consequently, nobody knew they were working with different clay until they fissured or burned in the oven. I have hundreds of bars of clay here, many with no dates on them, with no idea what batch they are from. I hate to throw them out, but they can't be mixed with each other & many of the experimental batches were horrible clay.
One great thing I found out while experimenting with all this was that translucent is very nice to work with and similar in quality to the old Cernit. I have been mixing a bit of color to it and using it with good results.....but am limited to what I can make with it. I have made a living sculpting dogs for the past 20 years & the translucent doesn't work for my dog line.
Again, thank you very much!
Warm regards,

December 31, 2011 AM 12:35:32 GMT+08:00

Hi Kristy, Yes I might be using a different batch as you and its not right for a manufacturer to do that, all the clay products must be at least 90 percent consistency, just like Fimo Classic or Premo which I've been working for years. I have got really warm hands and the Cernit soften even faster, whenever it happen, I will stop working on the clay and move on to other parts.
Yes 2 parts epoxy putty is the best and its hard like rock, there are basic colors and soon will have more range of colors.
Thanks for sharing, my wife was very happy with Cernit, maybe, I can try and test on the new batch.
Nice dog critters that you made, we love dogs!
Here 's our kids, wishing you a Happy New Year!

Best Regards,

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