As a rule, the recommended 160 °C for our porcelain brush pen ensures that the moisture is removed from the marking and the binder cross-links in the best possible way. This means that the best permanence is achieved. What remains is a polymer film. Put simply, the marking consists of a very thin layer of coloured plastic. As usual with plastics, it becomes critical at temperatures above 300 °C. The marking then burns and harmful substances can be produced. However, the application from the pen is very small, i.e. we are talking about a few milligrams of material that burns. We would therefore have no concerns about harmful gases, apart from the usual odour from an oven at 1000 °C. Visually, nothing more than a burn mark will probably remain.