making Acrylic ink with Acrylic Paint?

Ink and paint are very different things. However what you want to use it for can be done with acrylic paint.

You need to dilute it with water, ad some gum arabic to retain cohesion and a steady hand. You need to draw pretty thick lines and to keep these lines from flowing out you need the gum. It should be buttermilk thick. The wash is no problem at all You can ad some acrylic medium if it gets to wet but not thin enough. Acrylic medium is basically colorless paint.

What are you going to be using the ink for?

I think it would work, it is for a crazy marbling project using shaving cream