The edding 4200 porcelain brush pen’s paint only sets after having been heat-fixed in the oven. Christmas tree baubles aren’t usually ovenproof, so the paint won’t be able to set. Why not try one of our gloss paint markers instead? They come in lots of different colours and a variety of nib shapes and widths. If you use the edding gloss paint markers, you won’t have to heat-fix the baubles in order to set the colour.