Narrow

Ultra-narrow tape exists for details that will not accept a standard 8–10mm strip: a 6mm reveal in a cabinet door, a slot cut into a stone surround, the underside of a floating shelf, a gap between two panels that was drawn before anyone thought about lighting.

Narrow means less copper, and less copper means voltage drop arrives sooner. Expect a shorter maximum run than a wider strip of the same output, and plan the feed positions accordingly rather than discovering the far end is dim after the joinery is installed.

It also means less surface area for heat. Narrow tape belongs in an aluminum channel — in a wooden slot with no thermal path it will run hot and lose output early.