Black light puppetry is performed on a blacked-out stage lit only by ultraviolet light, so fluorescent puppets glow vividly while performers dressed in black become invisible.
The technique is sometimes called black theatre, and the Prague companies that developed it in the mid twentieth century remain its best-known practitioners.
How the illusion works
UV light causes fluorescent materials to emit visible light while reflecting almost nothing back off non-fluorescent surfaces. A puppeteer in matte black velvet against a black backdrop returns effectively no light and vanishes. The puppet, painted in fluorescent colour, appears to float unsupported.
What it allows
Anything. Objects fly, transform, separate and reassemble. Body parts move independently. A character can dismantle itself and put itself back together. Because the operators are invisible rather than hidden behind scenery, the puppet is free in three-dimensional space in a way no other form permits.
Materials are the whole craft
Fluorescent paint and fabric under UV, and genuinely black everything else. This is harder than it sounds — most black fabric reflects more than you would expect, and stage velvet or velour is used because the pile traps light. A single reflective zip or a wristwatch destroys the effect.
Lighting
UV tubes or LED fixtures positioned to flood the playing area evenly, with rigorous exclusion of every other light source. Any white light at all raises the ambient level and the performers reappear.
The demand on performers
You are working in near-total darkness, in black, often holding objects overhead. Blocking has to be memorised completely, because you cannot see your colleagues.
The hack: test your black under the actual UV rig before dress rehearsal. Fabrics that look identically black in daylight can glow faintly under ultraviolet.