Reflective

Tape

Orafol Reflexite

Reflexite seems to be the brightest reflective tape on the market. There are several versions.

V98 - more conformable for complex curves, stretches, can be repositioned, adhesive increases in strength over time

V92 - thicker, stiffer, less conformable, will not stretch, very strong adhesive

http://www.findtape.com/ was the cheapest source I found.