It depends on the bulb. “Black light” used to mean a very specific fluorescent tube tech with a specific wavelength output, but now there are all sorts of diff

It depends on the bulb. “Black light” used to mean a very specific fluorescent tube tech with a specific wavelength output, but now there are all sorts of different methods and wavelengths out there and each of them looks different to the eye (average vision and I’m assuming those with UV vision also). UV LEDs are the worst offenders for this as their spectrum can be all over the place even due to QC-passing manufacturing defects.