How do I apply a new coat of acrylic paint over existing coat?

I am trying to paint a glass jar with acrylic paint. Is there a certain base paint I should be using?How do I apply a new coat of acrylic paint over existing coat?
Why aren't you using a paint FOR glass? Acrylic is going to rub off.How do I apply a new coat of acrylic paint over existing coat?
Almost all craft stores carry paint that is made for glass. Regular acrylic paint won't work.