Can you emit black light

Ultraviolet radiation (ultra meaning "beyond") encompasses its own range of light rays, all of which are undetectable by the naked eye (of humans, at any rate).

UVA rays are the longest-wavelength, lowest-energy kind of UV radiation and the kind that is least harmful. It is the UVB and UVC rays in sunlight that cause the most damage, prolonged exposure to which can lead to sunburn and skin cancer.

Black light is a kind of UV light. Black lights emit ultraviolet radiation (UV light). UV is radiation with a wavelength just shorter than that of violet light, which is the shortest wavelength of light in the visible part of the electromagnetic spectrum. The electromagnetic spectrum is the range of radiation from benign radio waves to highly dangerous gamma radiation.
Black light sources may be specially designed fluorescent lamps, mercury vapor lamps, light-emitting diodes, or incandescent lamps. See our complete black light page.