About two weeks ago I was fishing up in the Sierras near the Sonora Pass. I went to add some tippet only to find it was brittle and broke when trying to tie onto the leader. Fortunately I always carry extra spools. My question is does tippet and leader for that matter have a definite shelf life? I think the brittle tippet was purchased 6 years ago. I store my tippet and leaders in a reel case in my closet when not in use.