It's a fabric that has shiny plastic circles on it, sometimes clear sometimes metallic that adds some sparkle to the fabric. It's usually sort of ugly up close and can look nice far away. It can look quite tacky sometimes, and I usually don't like it. However, I did recently buy a lycra costume that is made of a funky patterned glitterdot (where the dots are clear) and its actually really cute.
I'll post pics after my bra surgery is done...