Q&A for How to Make Molds

At any Home Depot or Lowes store, or on an online retailer.

Plaster of Paris for modeling molds or concrete if you want the model to be heavy.

Just make a regular mold, and coat the walls with the molding product. Don't fill the mold, but spread it equally against the inner surface and wait for it to dry.

If it's clay, then do the same as you would do for play dough and put in a bit of clay that fits the mold perfectly.

Try to reproduce a real model with a malleable material, like clay, which would be a replica of the sketch. Then, follow the tutorial to make a mold from it.

I've had good results with painting the mold surface with used motor oil just before pouring the concrete. Just don't use too much, a light even coat works fine.

You must use your artistic vision to sculpt the object in clay, preferably one that will harden. You can then make the mold from that.

Get the clay, then make it not too thick and not too watery. For example, if you want to mold a cup, use a real cup, then cover it with clay. When it dries, remove it.

Slime is not likely to conform to the shape of a mold, but you could try.

Try using a cast iron plated box for molding glass. It's what makes the cooling process a lot easier and slicker for popping out your molds.

Silicone is the easiest way, using 2 part silicone is the safest way to go and you’re guaranteed to end up with the result you want.