Review on 🔦 Findway UV Flashlight Black Lights - 12 LED UV Blacklight Detector Pack of 5: Ideal for Dogs, Pet Stain Removal, Bed Bug Detection by Wendy Williams

They all worked fine. I saw a video online that said bleach could be used on black light instead of invisible ink. I wrote several posts using bleach and it worked. Until the bleach dries. Then not so much. After purchasing ink for this specific purpose it worked fine. (So much for cheap labels.) I bought these to write high school scavenger hunt tips in invisible ink, then lit them black if they stuck. As I bought the ink after the hunt we weren't able to use it this year but are already looking forward to August to try again.