Protection question for sun/fading for PSA vintage and auto cards
 

I am collecting vintage PSA slabs (going from 1887 through the 70s) of key HOFers, as well as Lakers on card autographs. I have been displaying my vintage cards in a glass hanging display for the better part of 20 years. It does not get direct sunlight, but the room gets a fair amount of light. Now that prices have skyrocketed (very noticeable when I try and add a new card to the collection), I am getting concerned about the possibility of my encased cards fading over time. When looking at cards like 1952 Topps Jackie Robinson and 1958 Bob Gibson, there are about 100 different shades that range from vibrant to dull. I am assuming that this difference is due, in part, to how much light the cards have seen over the past 70 years. Is this accurate? If so, other than hiding my cards away in a box, is there any way to be able to enjoy them out in the open without risking long-term fading?

Similarly, I have read and seen alot about how sun exposure causes substantial fading of on card autographs over time. I have seen some beautiful cards with tragically faded autographs and want to avoid risking that happening to my auto cards. Does the PSA holder block UVA rays or do anything to protect against sun fading? Are there other sleeves or films that can be used to protect auto cards? I am curious what others on here do to protect valuable cards from fading. Thanks.

In my earlier days of collecting, I lost quite a few cards to sun damage. For what it's worth, red faded the most. The only solution I found that still allows me to display my cards is to completely black out all windows with dark curtains or shutters. This has worked well. The small doses of artificial light that they receive when I turn on the lights and look at them hasn't seemed to do any harm.

I'm not much of a graded card collector, but I doubt the cases provide any protection.

Display them behind conservation grade glass. That's about the only way to display and enjoy with some piece of mind.
Like Paul said, If you want to go to the extreme you can black out your windows with eclipse curtains and use specific very low uv light bulbs.

It depends on what the slabs are made of.

Polycarbonate blocks almost all UV, so if they're polycarbonate, they should be fine from UV problems that cause most fading.

That won't prevent problems from temperature cycling etc.