here's a thread of the master . . . http://hipgirlclips.com/forums/hairb...hi-flower.html
if i'm not mistaken . . . a 1/2 circle makes the petal in the pic . . . and it depends on how many needle gathers you take to get the pleats.
i'd guess it's fabric . . . as it's hard to get soft pleats like your pic out of ribbon . . . unless you've got wide satin.