Yes, it is possible to create black light letters!
Light letters with special black light-transmitting glass – “DayNight”. During the day, they appear as beautiful, solid black letters, and at night, they transform into signs with bright white letters.
The feature of this solution is that during the day, without illumination, the front side appears black, but when the LEDs are turned on, it becomes white.
This technology is significantly more expensive than a similar sign with white or colored glass. The main reason is that to “illuminate” black glass, a much more powerful light flux is required. Depending on the parameters of the letter element, it may require installing 4-6 times more LEDs than letters with white glass