Lay a drop cloth underneath the vase before painting to protect the workspace.
Turn the vase upside down, with the top of the vase flat down and the bottom section upward. This gives you the best position for working on all sides of the vase, as you will not be able to move it while painting when it is still wet.
Pour one cup of the first shade of purple glass paint -- the base color -- into a disposable container and dip a paintbrush into the paint to coat the bristles. It does not matter which order you paint with the different hues, as they are all eventually blended together.
Paint across the vase, reapplying paint to the brush as needed, to ensure a smooth, solid coat over all sides. Wait for the paint to dry. This should take about five hours; refer to the instructions on the paint to be sure.
Pour one cup of the second shade of purple paint into a disposable container and dip a sponge into the paint to coat one side.
Dab the sponge across the vase, covering over as little or as much of the base color as desired. Wait for the paint to dry.
Repeat painting with the sponge with as many different shades of purple as desired. Wait for the final coat of paint to dry completely.
Rub a piece of 180-grit sandpaper across the surface of the vase, rubbing gently and harder on areas you want to appear more distressed. Continue sanding the vase until you achieve the desired distressed look.