Question about using scupley before starting my first project

Hi there,

So I'm about to take on first project using polymer clay, my own Majora's Mask! I'm not going to make a cast of it to make more (that's way too advanced for me), it's just for my wall.

The base of the mask is a heart-shape, and I managed to find a wooden heart that is the size I was looking for. I figured I could use it like a mold and put the clay on it to make the heart shape. However, since it is wood, I can't put that in the oven with the clay to bake without setting my house on fire.

So my question is this, can I put something on the wood heart, like vaseline (or something else?), before I put the clay on so I can easily remove the wooden heart once I've made my clay version? Or is the clay sturdy enough that I can remove the wood without causing damage to what I've done with the clay? Since the wood is technically on the back of the mask, I don't really care if the back looks messy once the wood is removed, as I'm just going to hang it on my wall. I haven't used polymer clay before, so I don't know how removing the clay from the wood heart is going to work out.

Any answers/suggestions would be awesome! Thanks everyone!