greenLED
Flashaholic
Greenled is using an epoxy with powder and doing a smoothing out after the surface dries but before it dries through and through.
Not quite. The epoxy must cure on its own, and no smoothing is necessary. If you try to smooth the surface of the epoxy before it cures, you'll actually mess up the smooth finish. If you try to sand the surface after the epoxy cures, the surface loses its shine and it glows a bit less (you're destroying the GID particles by sanding them).
If you're subscribed to glowinc.com's newsletter, you'll see a tutorial coming out in the next month or so.