Can I put plastic cups that have been painted with the edding 4200 porcelain brush pen in the dishwasher, or will the paint wash off?
No, unfortunately not. The porcelain brush pens are primarily intended for use on porcelain or ovenproof glass. The paint only sets after having been heat-fixed in the oven, and is dishwasher-safe up to 50°C. Plastic cups can’t be heat-fixed in the oven and the paint would therefore wash off in the dishwasher.