Ultra-fine POSCA PC-1MR. Opaque water-based pigment ink writes on any surface and won't bleed through paper. 0.7mm bullet tip. POSCA works on most surfaces and is permanent on absorbent media such as paper and card.
Terracotta: Bake in the oven at 220°C for 45 minutes, then spray with varnish.
Textiles: Iron on the reverse side.
Porcelain: Bake in oven at 160°C for 45 minutes
Metal: Spray with varnish.
Glass: Bake in oven at 160°C for 45 minutes, then spray with varnish.
Wood: Spray with varnish.
Plastic: Spray with varnish.