Fill the balloon with water . This image illustrates why you don't completely fill the balloon you should always leave some room in the neck of the balloon, then as the form dries the pressure has somewhere to go and your clay wont split.
DIY Concrete Leaf Bird Bath DIY Concrete Leaf Bird Bath - love this idea! Those leaves look like rhubarb leaves to me. Hmmm may have to do something like this. Especially if I do a cob house some day, this would be a great wall feature/shelf.
What is this? A designed cube, a chair, or maybe a table? But it's so beautiful with the exposed wood, and the Kollektiv Plus Zwei founders Stefanie Högl and Matthias Borowski seem to have found that sweet spot between art, design and styling.