These clay tests that I have conducted, are for the benefit of all my students, you can always refer to this 
page if you are having problem baking with the various types of polymer clay. Clay creations begin 
with enthusiasm, fun, happy baking the clay project, will turn into disappointment if their works starts  
breaking or falling apart. To the parent preserving their kid's creative works as momentos, it must be 
strong and durable. As a handmade gift to friend, deteriorating item can be embarrassing. Parent 
and student question me about the durability of polymer clay and finally, I decided to conduct my own 
clay test. The baking temperature was recommended at 130ºC for 15 - 30 minutes, depending on its 
thickness. If you are busy and had forgotten about clay model baking in the convection oven, it is alright 
to leave your project in the oven for more than an hour at that set temperature, it will not be burnt or 
damage your clay work. 

If you are conducting clay classes the baking time are best set between 15 to 20 minutes, but the baking 
temperature should be adjusted, I will recommend the temperature setting after you have read my test.
As a professional clay artist for more than twenty years, it never cross my mind about the problem, until,
 I started teaching in tpolymer clay classes. Firstly, I have always design and made my creations with parts 
that closely integrated together, preventing the model from falling apart, if it does happen, it was probably 
due to poor clay adhesion, a little super glue will hold them together. Mixing clays also help to strengthen 
the polymer clay.
Any 3D clay model must be properly re-enforced with wires, toothpicks, wire mesh etc., this will prevent any
drooping of the clay model in the oven or falling parts, after baking. Do not touch or move the clay project
 after taking it out directly from the oven as it is hot and not properly cure. Touching the clay will dislocate the 
parts, it varies from different polymer clay, will not happen if the polymer clay have good clay adhesion. 
At this stage the clay should be left to cool before moving them. Choosing a proper oven for baking is 
important, use a convection oven or oven with temperature control and timer. Toasters without  temperature 
control are a problem with baking of the clay, you need to shield the creation from the heat, with foils and 
protect the base with ceramic tile, constant observation is a must while baking the clay model.

Choosing The Clay For The Test

There are many brands of polymer clay, basically, they are made with similar polymer base compound, some
 recommends a slightly higher temperature for baking. Although some are hard, some are soft, some are 
elastic, worst of all for children, are polymer clays that are hard and crumple with crumbs when you roll them. 
It is difficult and messy for kids to use them. There are also clays that are too soft, handling it with our warm 
hand, makes it even more difficult to shape our creation. I had used many different brands of clay and also 
intermixing them, makes them easy to handle, example, I have tried mixing elastic clay with the normal hard 
polymer clay, the result, it makes them soft, a little flexible and stronger after baking. You must mix at least ten 
parts of polymer clay to one part of super elastic clay, this process will also soften the hard clay but lighten the 
original polymer clay colors. Try and mix it yourself, you must be adventurous to experiment with the polymer 
clay. 

The Test

To test the polymer clay, I had used a convection oven with better heat distribution, this is my home oven 
which we had use it to bake cake. The clay is non-toxic, I had roll all the clays into a diameter of 6mm thick
and baked them for not more than 20 minutes at the various temperatures . 

Testing Begin At 130ºC For No More 20 Minutes

Du-kit

The clay is easy to handle and not so much effort in kneading, quality seem to be good, but not much choice
 of colors. Baking at the above set temperature, when the clay cool, is a little flexible and it breaks when bending
 the clay a few time with not much effort.

Sculpey III

The 3 series clay, is a very popular among all the children, it is soft and easy to handle by children from age 3
and above. There are wide choice of colors, in particular the red tends to stain the hand. The children and 
parent are a little annoyed at the situation as it will stained the other clay colors that they come into contact with. 
Baking at the above set temperature after cooling, it is rigid and brittle when you bend them. This is the reason 
why, I have been receiving complaints from disappointing parent and kids, that their work breaks even before 
reaching home. Been called Dr Clay I have fixed many damaged clay projects, the best way is to teach them 
to repricate the parts and replace them. I hope that the manufacturer will improve its formula, to prevent many 
disappointment, that will kill enthusiasm in clay creation. My students often play with what they create and also 
it is a memorable way to preserve your childhood creative works.

Super Sculpey

This is one of my favorite clay, for figurines and doll, feels hard, kneading it gives a good feel and easy to 
handle. It is a very popular clay for many professional artists and crafters, as it can be drill, carved after 
baking. I like the translucent effect on the clay. I had baked it at the test temperature and found that it is rigid
and hard, it doesn't breaks easily when bend needs a bit of effort. I once set it at this temperature and did not 
remove my art from the oven for more than 1hr and 30 minutes, it becomes very hard and it did not change 
color. Unfortunately, some time you get "mooning" spots which can be eliminated by adding another type of 
polymer clay. You can find out more about "mooning" spots. The size was 50mm x 80mm x 12mm thick. 

Premo Sculpey

This is a high quality polymer clay produced by Sculpey, it is comparable to Fimo Classic, but it is much 
more easier to handle than Fimo Classic. Baking time is recommended at 130ºC for 30 minute with (6.mm) 
thickness. Baking it and cool down seem to be a little flexible when bending, it also breaks, this is due 
to the shorter time in baking and temperature setting. Flexibility is probably due to its thickness, I had test 
clay with 1.0mm thick it is flexible though at a higher temperature overall it is stronger than Sculpey III.

Fimo Soft

Fimo clay is in the market for more than twenty over years since I started to used the clay. The soft clays 
was introduced later to the public, overall the colors are wide and I really likes its color ranges.
Unfortunately, it is not that soft, I find that the clay ranges have inconsistent softness. I had to spent time 
pre kneading the clay for my young students taking away some of my teaching time. The crumbs can run 
out of control on the table and floors if you allow the students to roll them. There are certain color that are 
reasonable soft to handle as they do not produced crumbs. The red colors are bad just like Sculpey III, also 
stains your hand,  One good way of softening the clay to prevent the crumbs, is to roll the clay with its 
packing wrappers. The baking and the test, shows the clay to be even more brittle than Sculpey III, it is rigid 
and brittle.

Fimo Classic

Once I was in love with Fimo Classic, the quality had change, the clay is hard not like before, it is not as 
hard as Sculpey original white clay. Fimo Classic color ranges are lesser than Fimo Soft, its quality are 
comparable to Sculpey Premo, but it is also difficult to handle for young children. The clay produced lots
 and lots of crumbs, as you rolling it on the table. It is messy if you do not have the patient to condition it. Fimo 
Classic was created for only for the experience and professional clayer, the quality is comparable to Premo. 
But if you used Premo and Cernit, you will not like to use Fimo Classic as the clay is more messy when 
conditioning the clay. As I test and baked at the temperature of 130ºC for half an hour, it is like Premo, a little 
flexible then it breaks after bending it a few time.

Cernit

This is another German polymer clay and also in the market for a long time, I find that the quality is very good, 
and strong  comparable to Premo. I consider it as a professional clay, you must use it to experience the feel 
of the clay. With wide ranges of colors, I like some of their soft pastel colors. I noticed that the clay are a little 
translucent in appearance, the feel is very good and easy to handle. When baked, it is also a little flexible, then 
it breaks if you bending it too many times. Like Du-Kit, Premo and Fimo Classic, the set temperature is a stable 
setting for baking polymer clay. Quality is good for smaller modeling and fine detailing. Eventually, clay adhesion 
plays an important role in durability of your model when you add tiny details, without relying on super glue to 
fix them, especially very tiny parts.


TEST CHART ON VARIOUS TEMPERATURES

Warning Note: If you set at the above temperature, there are unpleasant fumes emitting from some of the clays, avoid smelling the fume, 
it is nauseating. There is no reason to bake at the above temperature unless it is only for special effects, under professional supervision.

      
 


      
Baking Temperature At 150º
      C

      
  


      
Baking Temperature At 200º
      C



Baking Conclusion 

As the result shown after testing, I prefer to set my temperature to 150º C, with this setting, you should not 
bake beyond the 20 minutes, set an alarm to remind you. If you have the time, the safest temperature setting
will still be 130ºC for more than 30 minutes and even 45 minutes will be OK, but if your oven is faulty the 
result cannot be guarantee under such circumstances. Use an oven thermometer to check the temperature.
The baking result at 150º C shows five type of clay to be tough and durable, they are Du-Kit, Super Sculpey,
Premo Sculpey, Fimo Classic and Cernit. 
My prime consideration for my young students is to select polymer clay that are easy to handle and durable.

I will start with the most difficult to handle among the five clays, Fimo Classic is a quality clay, the most difficult 
to use, it is hard rolling it create lots of crumbs and most kids, refused to roll the clay, as it will mess up the table, 
I feel that it is only suitable for the experience and professional clayer. The next is Super Sculpey, a good 
modeling clay, a favourite for hollywood modeler. I personally like to use it for figurines, dolls, puppets, animals 
and other application relating to plastic hobby crafts. Beigh in color, I just love that slight translucent effect in the 
clay, unfortunately, they don't produce other colors. The initial contact with the clay appears to be hard, but when 
you handle it, is easy to knead soften easily without producing crumbs. The next clay is Du-kit this is the clay that 
is strong and glossy (looks like vinyl) when baked. The quality is good, my student likes the clay and I like it for 
its durability. 
My initial love for polymer clay was Fimo Classic, but after using Premo Sculpey, I change my mind. 
Firstly, the quality is comparable to Fimo Classic, it is much more easy to handle, rolling it does not produce 
any crumbs, all my students are able to knead the clay without much effort. Lastly, Cernit clay is also a very 
good and tough clay, generally can be use by all. I love the feel of the clay, it is also one of my favorite, you 
can use it  immediately without much kneading. Living exposed polymer clay to the environment will makes 
certain clay harder to knead, but Cernit will not give you that problem.
The final result, narrow down to four types of polymer clay which are tough, durable and easy to handle, 
they are Super Sculpey, Premo Sculpey Du-Kit and Cernit.

The Above Test  is only conducted for the benefit of my students, your test own results might differs from mine 
in testing the clay. Overall baking at 130ºC temperature setting is stable but my preference is 150ºC which 
is my choice of temperature setting to bake the clay for my students, if you are acceptable to my test result
you are welcome to follow my recommendations. 



The Clay Adhesion Test

Clay adhesion is very important when you are creating tiny miniatures, such as 1.0 mm to 5.0 mm in size. It 
will be difficult to use super glue to hold the tiny figurine, it might mess up your creations. I have students 
already creating very small miniatures, therefore, by conducting the test it will be benefit themt when baking 
their clay projects
To test the clay, I had roll the different brands to the size approximately  20mm x 3.0mmø x 2, crossed them 
and pressed them slightly together, sent them to bake at the temperature of 150ºC for 15 minutes, the results
 are as follows:

Du-Kit

Moving the crossed Du-Kit Clay like using a hand held grass cutter, takes 3 times to separate the clay.

Sculpey III

Moving the crossed Sculpey III Clay like using a hand held grass cutter, takes 10 times to separate the 
clay.

Super Sculpey

Moving the crossed Super Sculpey Clay like using a hand held grass cutter, takes 9 times to separate 
the clay.

Fimo Soft

Moving the crossed Fimo Soft Clay like using a hand held grass cutter, takes 7 times to separate the clay.

Fimo Classic

Moving the crossed Fimo Classic Clay like using a hand held grass cutter, takes 26 times to separate the 
clay.

Cernit

Moving the crossed Cernit Clay like using a hand held grass cutter, takes 18 times to separate the clay.

Conclusion

The above test results show that Fimo Classic is top of the list for good clay adhesion. If you are prepare 
to do more clay rolling, then Fimo Classic is the most suitable for tiny miniatures without worrying about 
breaking your tiny miniatures even, if you picks it up with your fingers. The next alternative is Sculpey 
Premo and Cernit, you too should also be able to enjoy creating tiny miniatures and not been afraid to 
hold them with your fingers. If you mixed both of them, it will be stronger, try mixing other clay will have 
different results. Your clay miniature will be durable if you mixed with quality clay. To enjoy polymer clay 
creation, just relax, create and bake the recommended temperature setting is 150ºC for 20 minutes.

Good Luck!

Garie Sim



More About Polymer Clay 

Creative Clay For Creative People
Garie Sim's 101 Polymer Clay Information, Tests And  Experiments