| Clue | Source | Date |
|---|---|---|
| Invisible ink? | The Atlantic | 02 Oct 2025 |
| Body art that might be visible ' only when exposed to a backlight | ||
| Body art that might be visible only when exposed to a blacklight | USA Today | 10 Apr 2025 |
| Art that can fluoresce | Newsday | 20 Apr 2019 |