ancient thread but I did some research on this. Hopefully I can post as guest.
Krylon UV archival is removable, ammonia removes it. ( ie windex applied to a paper towel ). Its designed for art restoration. I tested on watercolors, the matte is entirely invisible, it removes some of the glare/reflection when the paint is applied thicker and thinner, giving the picture a more even sheen ( a way to tell if its applied if you know what to look for ). After testing this is all I use. I think the golden protects a bit more. When I spray it, I spray a very heavy multiple coats.
Tested this on a painting with liftable colors. Used a an art restorers approach - soaked paper towel in windex, then lifted wetness with paper towel. Was careful to do it so it didn't disturb the pigment. Took days just slowly doing it, until it no longer was protecting the pigment, and i could lift it, and paint on it again. Basically trial and error. It would not be something you could do easily, rather its something where you take it really slow ( like if you were an art restorer ). I usually use staining pigments, these should allow removal a lot easier. Remember you are effectively getting the painting wet, so you need some skills here to not damage the painting.
The idea though, is if the painting is covered in dirt, spray paint, vandalism ( a painting of a pride flag on the california tower in balboa park was vandalized by movers ), you can remove just PART of the varnish, the top part, which means its perfectly clean, then you reapply the varnish.
A better strategy is to use this as the base varnish, then use ANOTHER varnish on top, which is soluble by something besides ammonia, which becomes a sacrificial coating.
It provides protection in three ways.
*Blocking UV light - effect degrades over time, so it should be re-applied periodically.
*Blocking ozone, oxygen, and other pollutants - these accelerate degradation - its not just light damaging it, plus it is blocking dust. It effectively makes the watercolor acrylic. A lot why watercolors fade faster, is they are exposed to the air, which makes the air interact with the pigment and the light energy. By encasing it in oils, acrylic, any other medium via varnish, it responds like an acrylic or oil painting.
*Allows washing with a damp cloth ( no ammonia ). If damaged you can use a teeny bit of ammonia to remove a teeny bit of the surface, so you can clean it. Then you reapply the protective spray.
If you select lightfast paints - rated wool scale of 7-8, you should be able to just use plexiglass/glass glazing. As per testing on handprint.com ( or individual artists doing this exact method, the ASTM is rating acrylics, not watercolors, I look for a description of the testing, if that is secret, it is useless - Golden, Daniel Smith and Winsor Newton have their own labs, they generally are reliable even if other brands are not ). There is no excuse if you are using paints which aren't reliable in watercolors - the only exception might be the bright pinks. Note that chinese white fades too ( becoming more transparent ), this isn't picked up in testing. If you see bright pink ( opera rose ), you SHOULD say, this will fade, use UV glazing.
After doing watercolors, I tried buying acrylics, and even going thru goldens vast selection, they tend to not have pure pigments, and the pigments often have ones that are questionable in watercolor - sure they are better due to the medium providing protection, but I just decided I could not trust them - I've been spoiled by knowing my paintings are rated at over a lifetime.
I would use uv glazing in addition, but as an artist I usually am trying to limit costs, because I use paints rated for over 100 years in interiors, I don't see it as required. I would include any details as to what treatment the picture has, so an art restorer 100 years from now can know this picture had such and such krylon.
I don't see the need for using the UV spray unless the painting is unprotected - ie gallery wrapped not needing glazing.
If you blast the hell out of it, and use reasonably lightfast paints, it should be good enough to not need UV glass, but after decades the UV blockers will stop working. Not sure the interval for reapplication, thinking it might be 5 or 10 years, and you just make it thicker. Not a big deal because an art restorer can undo the varnish, if you mark on the back what you did and when ( if they know what you used )
I am found via artbybrianmeyer - usually on insta but probably not for much longer.
Rick
