Home-Made Whiting?

Question

I'm doing a project for school in which I use paper mache.
I'm creating "mash" out of mashed up newspapers soaked in water overnight and then draining it. I'm going to use it to create a sculpture thing.

But the problem is, the ink in the paper made the mash all gray because it was dilluted overnight.

So I read in a "How To Do Paper Mache" book, that you could just add "whiting" to make the mash bright white and porcelain-like looking.

I was wondering where I could get this. I know pure whiting is made of calcium carbonate. So could I just go to my drive way and pick up some crushed shells and crush them up into powder form? Because thats what their shells are made of.

Should I do that, or go out and buy some?
I don't want to waste money when what I'm looking for is in my front yard.

Answer 1

Most people just make a gray sculpture and then paint it when it's done. Whitening is probably some really strong chemicals.
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