Incandescent Blacklights
There are incandescent bulbs made with deep violet-blue bulbs which largely filter out visible light. Longer UVA wavelengths get through the glass and are not blocked by the dark colored filter dye. Most visible violet and some visible blue light get through, as well as a wide range of infrared and the longest, less visible of visible red wavelengths. Some traces of other visible wavelengths get through.
These bulbs are a convenient source of some UV to cause fluorescent paints, dyes, and other substances and objects to glow. Most of such fluorescent objects (especially magenta, red, pink, orange, yellow, and green ones) also glow from visible violet and blue light.
These bulbs are quite safe, although it may not be a good idea to stare into one from short distances for long periods of time. They generally have hotter running filaments that last only about 500 hours or so.
Fluorescent Blacklights
There are fluorescent tubes that emit UV. The phosphor coating on the inner surface of the tube absorbs the UVC emitted by the low pressure mercury arc, and emits longer UV wavelengths. There are at least six different UV-emitting phosphors used in fluorescent lamps.
One common lamp is the ""BLB" fluorescent lamp. The tubing is made from a very deep violet-blue glass known as "Wood's glass". The tubing is quite transparent to medium and longer UVA wavelengths, and shorter visible violet wavelengths, and a fairly broad range of infrared and the longest, least visible red wavelengths. These tubes emit lots of UV mainly between 350 and 375 nanometers, some of the 404.7 and dimmer 407.8 nM violet mercury lines, and just enough of the blue 435.8 nM mercury line to have a basically blue color when lit.
The "BLB" lamps are used for special effects due to their ability to make fluorescent objects glow very brightly.
There is a less common deep-blue-violet lamp with no phosphor and made with special glass (maybe quartz) to transmit the 253.7 nM UVC (shortwave UV) mercury line. These lamps are generally used to make fluorescent rocks glow.
There are UV fluorescent lamps with glass not dyed to block visible light. This includes the BL and the similar 350BL. These are often used to attract insects into electric insect killers. The 350BL has a broader spectrum peaking at a slightly shorter wavelength (350 nanometers) than the BL does, and is supposedly more attractive to insects than the BL.
There are other ultraviolet lamps such as UVB medicinal lamps and UVA suntanning lamps.
There are also the similar fluorescent actinic lamps, producing long UV wavelengths and/or visible violet.
These are sometimes used in some special photographic and printing processes. One of these is specializing in producing visible violet light. The 03 is also used in reef aquariums with live coral since coral utilizes violet and deep blue wavelengths. The 03 actinic will cause fluorescence of most fluorescent dyes, pigments and paints, especially other than ones which fluoresce blue.