White residue around edges of case or on surface of mug

[socialgiraffe]

I agree on the diagram, however I think it is something like the following:

Push button once, top oven
Push button again, both ovens
Push button again, all off

[Andrew]

We have had this on mugs and metal in the past. Like a powdery white coating that you can scratch off fairly easily. Whenever this has happened it is down to the coating melting at a lower temp than normal. When it melts the fibres from the paper hold in the coating leaving get the residue. Had it on several different items over the years but never a plastic such as the 3d cases. Lowering the temp/ time has always been the solution on the items we had but to be honest, I didn't think the 3d cases had a coating. Thought the composite Plastic was what the ink was holding to rather than coatings like most items.