I noticed this today on the U-40 Faq page, and hadnt seen it brought up here before...not that I'm pro or con but thought it was interesting:

Will color Lock prevent the threads from fading due to UV exposure?
A No. None of the color preservatives act as a UV barrier. They are a barrier against the final finish changing the color of the threads, but have no anti UV characteristics. Tests have shown that the threads that are susceptible to UV deterioration—blues and reds especially—actually deteriorate quicker when color preservers are used.

Not surprizing! I would guess that it might be due to the fact that with no CP, threads are so dark. fa`ding might not be so noticeable. Strictly a guess on my part! I have no actual knowledge of that kind of stuff!

I wonder if that holds true of all CP's?? I haven't noticed fading on my rods - YET

Mike

I had terrible fade problems with lighter nylon threads with CP. Never tried them without. Switched to metallics and no CP. Problem solved.

Putter
Williston, ND

All my light colored threads behave the same way, CP or not. If the fisherman really, really, really keeps his stuff in use and in the sun, the yellows and light blues will fade to a soft pastel color in a couple or three seasons.

I sort of think all thread fades but with darker colors you're starting with more color depth to begin with so it would take longer for it to really be noticeable. The sun fades everything from thread to the paint on your car or the fabric color in your car seats.