Favored for its strength and resistance to fraying, 6/0 Uni-Thread comes conveniently pre-waxed and measures a perfect 135 denier. Perfectly suited for wide range of fly sizes, Uni-Thread is carefully constructed from spun polyester and exhibits very little stretch under tension. Semi-flat when laid or easily twisted round at the tier's discretion, we offer 6/0 Uni-Thread in a wide array of wonderful colors certain to please.