does all clear colorless vinyl yellow over time?

Is there anything you can do to prevent it? Is it exposure to Ultraviolet? Normal aging?

I believe Frank ahd a thread on KR a while back and said its basically smoke and sunlight that will yellow clear vinyl..My girl thinks i'm a freak(which i am) because i keep the shades drawn in the office where my displays are..

I was going to put mine in the freezer...

I try and keep my toys in the dark.
I have a marmit clear Dogora that got really yellow I think because It was on a sun exposed shelf all the time.

Frank seemed to have a great setup where he had displays that appeared to be in front of windows with blinds. So it gave some backlighting to his displays.

Dude, I'll call you on the freak factor and raise you two hundred.

My bedroom windows are covered in aluminum foil wrap.

Gotta keep out those CIA mind control beams.

SOme of my 70's stuff is super yellow-brown, and brittle. I'm guessing it was left out in the sun a lot.