Here's what the boys at Orvis have to say about their Mirage Flourocarbon Tippet Material:
Characterisitics: Very strong and nearly invisible in water. Impervious to UV. Slightly stiffer and more abrasion resistant than Super Strong tippet. Fluorocarbon tippet sinks quicker than nylon.
Applications: All fishing conditions where an abrasion-resistant, low-visibility material is needed. Great for leader-shy trout and saltwater species.
The strongest fluorocarbon material available, stronger than Super Strong nylon in sizes 7X-0X.
Completely resistant to UV and will not absorb water: Retains abrasion resistance, knot, and tensile strength regardless of exposure to the elements.
Reformulated Mirage features improved tensile strength and elasticity, making it easier to knot without sacrificing its superior abrasion resistance.
A refractory index of .09 makes it virtually invisible to fish (Super Strong Nylon has a refractory index 1.53)
Specific gravity of 1.76. Mirage breaks surface tension quickly.
Made from PVDF (polyvinylidenfluoride)
Available in 40-meter stackable spools that snap together. Compatible with Tippet Spool Holder.