River Silks 100% silk ribbon is woven individually, not cut from cloth. It has selvedge on both sides and has a high thread count, which makes it the most durable ribbon available. 5-1/2 yards per spool.  OD means "Over-Dyed" which means the ribbon has been dyed in a base color and then another color applied.  All colors listed in 4mm are available in 7mm and 13mm and can be easily ordered!