There are several different types of paint you can use to paint mugs, but the paint you choose and the steps you take to protect the design depend on the mug's surface.
Turn a mug into a miniature chalkboard with one of the special chalkboard paints created for unglazed and glazed ceramics. Once dry, this type of paint works just like a chalkboard, allowing you to write on the painted surface with chalk. Check the chalkboard paint's label to find out which types of ceramics it is suitable for, how to apply it and how to wipe your slate clean when you want to write something new.
Acrylic paint is also suitable for most ceramic mugs. However, some acrylics are designed specifically for unglazed ceramics. Check the label before purchasing.
After you paint your mug and allow it to dry, use a clear sealant to add shine and prevent the acrylic paint from cracking.
Baking Glazed Ceramics
While a sealant will work for some glazed ceramics, others need to be baked in order to make them dishwasher-safe. After the paint dries, place the mug in a cold oven and set the oven to 350 degrees Fahrenheit. Allow the oven to come to temperature for about 10 minutes, then bake the mug for 30 minutes. Turn off the oven. Do not open the oven until it has cooled completely.
Plastic Mug and Metal Mugs
Most paints used for ceramic mugs will also work with plastic and metal mugs. There are also paint pens and spray paints specifically designed for plastic and metal surfaces. However, plastic and metal mugs cannot be baked to seal the paint. Instead, use a clear plastic sealant to add an extra layer of protection.
Paint is likely to chip off plastic and metal mugs even when a sealant is used. To stave off chipping and peeling, hand wash only.
If your mug is glass, you have a few options: paints made specifically for glass, acrylic paint and glass paint markers. One type of glass paint air dries and does not require any special finishing. The other type requires oven baking to ensure permanency and that it will be heat-resistant and waterproof. Check the paint's label carefully to verify which type you are purchasing.
If you want to draw a design on your glass mug, consider glass paint markers. These are ideal for creating small details and letters.
You can also use acrylic paint on glass mugs, though you will need to add a sealant as a final step to ensure the paint does not chip.
Always prime glass before painting it by wiping it clean with a tack cloth.