Welcome to the Cake Decorators Q&A

I would like to make some dummy cakes as I want to practice more decorating. As I am new to this I was wondering how I would carve the polystyrene to make the Teddy bear cake and other cakes that need carving? Where do most people buy the dummies from?

Carving dummies will be quite difficult and messey and they are not cheap. I would make rice krispie treats and mould into the shape you want. You can use really cheap butter, and Krispies.
If you know the sizes you want , then get tins etc so you can put your mixture into them and then you would not have to carve much away.
Hope this heps, but I am sure other members will give you some answers as well.
Good luck

Hello Tomandhen123

Paul recommends http://www.dummiesdirect.co.uk/dummiesdirect/index.html The company will make any shape dummy you want. I use them for all my dummies. Prices are competitive and service excellent.
Dummies are a great way to learn piping and decorating skills but not carving. You would be better off using RKT to learn carving. Carved krispies can be kept and remoulded, I’ve done it and it does work quite well. Jackieharris is correct in saying they can be difficult to carve plus make a heck of a mess. If you can get your hands on stale tin loaves, they’re good for carving practice.

I was thinking more to cover and decorate cakes to show in shop window for a long time. Would it be ok to use carve Rice Krispie bars?

In which case dummies is the way to go. RKT will eventually break down and won’t last as long as Styrofoam.
Depending on what you’re carving, rice krispie bars would cost a great deal more than dummies which can be reused for years afterwards.