Just the shape of the sphere. There's no detail. I need to make a skin to attach to the sphere.If you could post a picture of what you're trying to cast, it would be easier to provide some advice. The problem being is that we have no idea of what detail from the sphere you're trying to replicate.
I have a 20 inch polycarbonate sphere. I need to make a mold of a 12 inch section of the top of the sphere, use the mold to make a plaster plug to vacuum form over. What would be the best way to make the mold off of the sphere?