StampOsaurus Craft Supplies

 This incredible gel ink pen writes in metallic silver and automatically creates a brilliant colored border as you write! Create a piece of art with every stroke! Dress up your words or signature by choosing from the five contrasting border colors. Add excitement in your notes, cards, and invitations. With a 1.0mm ball for a bold line, Silver Shadow dries instantly. The outlining effect is best achieved on white, un-coated fibrous paper. No need to shake, pump or squeeze
— just write like you would with any gel pen.

You can use them on light card, dark card (come out silver), acetate (fab for tropical fish) and you can also water colour with them.