You may already have figured this out. If you have great, if not, keep reading. Early on I was blessed by learning about polymer clay from some many great teachers online, one I discovered was, Cindy at The Polymer Clay Tutor . Cindy's research proves that accurate temperature and the length of time firing in your oven matters greatly to achieve optimal strength, steering away from the manufacturer's bake times.
Needless to say, I have heeded Cindy's advice, and can confirm that she is correct, short times as directed on the packaging, doesn't leave you with the strongest clay pieces possible.
The fact that the manufacturer's package doesn't provide the bake times that are best for strength, puzzles me. Premo by Polyform, says bake at 375 Fahrenheit for fifteen minutes per 1/4 inch of thickness... Why wouldn't they tell us one hour? They must know, don't they? And then the further I head on into my polymer clay journey, the more mixed messages regarding firing time appear! Frustrated, I know! Mostly because the package should have the best bake times for strength possible. Makes sense right!?
Unfortunately, we have to get used to the mixed messages regarding bake times because they are conflicting every where I look. In fact, I recently have been enjoying watching hours of the UK's Jewellery Maker Channel while I work. A large variety of Jewellery Maker shows feature Designer Inspiration and Master Class segments, to promote the products they sell, learning how to use them and to offer inspiration to create. And one favourite artist I really like watching there is from the UK, Debbie Bulford. Jewellery Maker sells Premo/Sculpey polymer Clay and Debbie offers great techniques and ideas working with the clay. But, she also says to bake it at the minimal amount of time as the manufacturer's directions state. It is clear that she is a credible, legitimate artist who knows polymer clay well and that Jewellery Maker is trying to sell the product she is representing. I am wondering if making it appear as easy as possible to use (offering quick bake times) is part of why watchers aren't told about the need to increase baking time. Maybe it is why the manufacturer of the clay itself, Polyform/Sculpey doesn't change the times on packaging either?
On that Note, I am disappointed every time, when I hear a tutorial tell us to just follow the package of clay directions.
Polymer Clay Lesson Learned....
1. Always bake your work for at least ONE HOUR no matter how thin your clay piece may be. Based on my own experience, I totally affirm what Cindy Leitz taught me from day one! It sure can get confusing when even the manufacturer or sellers of the clay are not giving the best advice available.
After learning from her and some others online, it was clear that firing it for at least one hour, even if it is 1/4 of and thick, makes it stable and stronger. if you don not have the correct oven temperature, then yes, you can burn your work...keep reading....
Too Hot! Too Cold!....Just Right....
Side note: And yes, actual temperature matters as well. We discovered that our toaster oven was off by about 30 degrees! (make sure you use an oven thermometer to insure correct firing). At first, my thinner pieces were snapping and had zero stability if not more than a half inch thick. Once we followed Cindy's adamant directions, we bought an oven thermometer, increased the temp accordingly and all improved. If your oven is set to the exact package temperature, no matter how long or how many times you bake, you can not burn the clay.
Another key step, sometimes not emphasized by lesson providers or on clay packaging...again to help achieve the best strength, condition all polymer clay very well! Including the super soft stuff! It means smooshing/mixing or repeatedly passing through clay machine, combining all of the ingredients together leaving you with stronger clay. Takes 5-10 minutes.
WATCH: Polymer Clay Tutor Cindy Lietz Videos about Baking Polymer Clay