Uv markers, so many uses i think i will have to go get one immediately! You might have out flowers in food coloring when you where a kid, anyway imagine this with a broken apart uv pen. Glow in the dark flowers, now wouldn’t that be something? These guys here have done it, and they will show you how to.
Other common uses for the ink in UV sensitive markers are glow in the dark bottles (think college party), or really any surface you can cover with paint. Maybe a street number sign, which glows in the dark? Yeah i like this idea!