A product that I have never seen before is on Brodak's website.  It is a U. V. blocker.  Expensive item.  Has anyone used it?  It might help minimize color fading but what about yellowing?

I have noticed yellowing on some of my planes.  It is noticeable in areas that had been painted white.  It might be the clear dope yellowing.  Maybe this happens over time regardless of how much sun exposure although sun exposure probably speeds up the yellowing.

The clear topcoat I used on these planes was Brodak clear but not the crystal clear.  The crystal clear is colorless whereas the other version of Brodak clear has a slight amber tint.

On my latest plane I used the Brodak crystal clear for the first time for the clear topcoat.  Not enough time has passed to see any yellowing.  I am hoping the crystal clear is more resistant to yellowing than the other version of Brodak clear.

Any others with similar experiences?  What steps did you take to preserve the finish?

Since Randolph make Brodak dope and I can buy the Randolph label for much less, I also have some Randolph clear, both tautening and non-tautening.  The tautening version has the amber tint while the non-tautening version is almost as colorless as the Brodak crystal clear.  Why the difference?  Is there a tautening agent that causes the amber tint?