I've heard the High Power's retro-reflective properties work about the same as a glass-beaded screen except the beads are much smaller. So, I'm wondering how glass micro bubbles would work. They are roughly the diameter of a human hair and they are used to make lightweight filler when working with composites. It would be interesting to try them in a screen coating. You could mix them with clear lacquer or maybe spray on a coat of lacquer over a white base and then dust the bubbles on. Follow with coats of flat lacquer to prevent hot-spotting. The bubbles look and feel about like talcum powder. Cost is about $7 for a pound bag which is about a gallon.
http://www.aircraftspruce.com/catalo...es/bubbles.php
http://www.aircraftspruce.com/catalo...99/bubbles.jpg
http://www.aircraftspruce.com/catalo...es/bubbles.php
http://www.aircraftspruce.com/catalo...99/bubbles.jpg