Dip a clean rag into warm soapy water and wring out the excess water. Wash the porcelain thoroughly, rinsing the rag as necessary.
Buff the porcelain dry using a soft cloth.
Sand the entire surface area of the porcelain with 250-grit sandpaper. Wipe away any dust with the soft cloth.
Paint the porcleain with an oil-based semi gloss paint with a paintbrush. You may choose to paint all the porcelain the same color or use different colors in a specific design.
Allow the paint to dry completely.
Apply a layer of urethane over the painted porcelain to protect it from damage.