I saw a marbelized clay pot about a week ago--using acrylic paint?

you can search this on hometalk - put "marblelize" in the "next project search bar.

yup. its an old japanese technique, called suminagashi - it was originally used for royalty on documents and then later for paintings; but many use nail polish. However, you can use acrylic paint as well. i would recommend a primer on it first to hold the paint - Same applications apply, most use white paint for background base, but you can choose whatever color/many colors you'd like. pour slowly into old pan or plastic container, don't mix - SWIRL slightly, then lower pot into mix and turn. lay on a clean surface to dry - i would not recommend newspaper, perhaps counter top or an plastic cutting board, a piece of wood, etc.... there's many sites out there with many different ways to do this - pick whats best for you