Traditional red flocked polypropylene ribbon is satiny on one side and velvety on the other. Suitable for both indoor and outdoor use -- this is the one to use on outdoor wreaths and garlands; it will hold its color in the elements.
Non-woven so it won't ravel. Stiff enough to hold its shape well too.
#3 ribbon, 5/8 of an inch wide on a spool of 25 yards as shown.