Rufflette
/ˌrʌf(ə)ˈlɛt/noun
A trademark for: a kind of tape that is sewn to the top edge of a curtain, having slits at regular intervals at which curtain-hooks may be attached, and cords threaded through that enable the tape and curtain to be gathered or ‘ruffled’.
Origin
1930s; earliest use found in The Trade Marks Journal. From either ruffle or ruffle + -ette.