Most paint and colour is added to ceramic vases during the glazing process or just before. The glaze on a ceramic vase is actually small powdered glass particles that melt in the heat to create a hard surface over the vase. This smooth surface is somewhat difficult to paint over, but not impossible. If you roughen up the surface of the glaze enough and use the right kind of paint, you can paint over the ceramic glaze on any vase. The painting process will take about a week to complete because each part of the painting process must dry thoroughly before you can move on to the next.
Clean the outside of the ceramic vase using an abrasive cleaner and a scrub pad. Rinse the vase with clear water and allow it to dry overnight.
Draw the outline of the design that you want to paint onto the vase with a permanent marker. If you want to paint the entire vase rather than a small portion, skip this step.
Paint the design onto the vase with the paintbrushes. If you have several coats to paint, paint the base coat and allow the vase to dry for two hours. Add the next coat and allow it to dry for two additional hours. Continue to add layers of paint, allowing the previous layer of paint to dry before proceeding to the next layer. Allow the last coat of paint to cure for three days.
Apply a coat of water-based urethane over the entire vase. Allow this coat to dry overnight. Apply a second coat of urethane and allow it to dry for 24 hours before using the vase. The urethane acts as a sealant and protector for the paint and will prevent chipping, peeling and fading.