An idea for my handcraft works!

I would suggest that you should first build up the round body of the piggy bank in papier mache. This will make a stronger product which you can then decorate with cold porcelain, adding detail such as ears, nose, legs and tail, perhaps. There are two ways of doing this. The first method uses a small balloon inflated to the size you want and you then build up the body with torn paper pieces or strips. When the papier mache has hardened, you deflate the balloon and remove it through the small opening you have left for the neck of the balloon. With the second method, you make the shape with a non-hardening modelling clay (such as Plasticine). For this, you will either have to make your body in two halves or cut it once the papier mache has dried so that you can remove the Plasticine. You then join the two halves with more paper strips. This method is very good for more complex shapes (for example, for masks). From what I understand of your cold porcelain, it is not very strong on its own and also needs to be made in reasonably thin layers (otherwise it will take forever to dry out). For a piggy bank or a decorated mask or something similar, you would need a stronger base over which you would apply your cold porcelain decoration.

It s a good thing you have a hobby I am waiting to see your sweet piggy bank. Doy consider selling them. You can make some money from your talent.