Paint porcelain mugs with a porcelain pen and make your own design. The best thing about the pen is that you can easily wash off the design and start over if it doesn't turn out well; then you can harden the porcelain in the oven. Here, we made stylish graphic patterns with a black porcelain pen. Remember to thoroughly wash, rinse and dry the porcelain and to not touch the surface to be decorated before you start painting. Harden in the oven at 160°C for 90 minutes.