From the manufacturer:
Great for handmade cards, doodles, drawing, line borders and lettering, Gelly Roll Gold Shadow Pens features incredible gel ink that writes in two tones: gold metallic outlined in another contrasting color! No need to shake, pump or squeeze just write and see the magic. The 1.0mm ball tip creates a bold line that dries in a few seconds. The gold metallic color is brilliant and the contrasting outlining effect is best achieved on white, uncoated fibrous paper. Meets ASTM and ACMI non-toxicity standards and is AP seal certified.