Glass alone will not save your Artwork

[Nic 68]

Remember, we will talk only about glass. The board, the frames with its lacquers, the tapes used and the climate of the storage area is another huge subject.

Back to glass, it’s a common mistake that framing under one million dollar museum quality crystal will save your artwork.
The fact is: if you can see the painting, the painting can see the light. As a conservation expert that sells products to Gallerie degli Uffizi in Florence once told me, UV is dangerous but all of the remaining frequencies will also make damage over time.

Don’t hate me, but the best way to preserve your painting is by storing away from light it in a completely climate controlled environment.
Second best is a climate controlled room with no other lights than LED lamps. Or, as Steinar Lund once suggested:
"Make a giclée of what you want to hang on your walls and store the original."

What increases the problem is that most of the artworks that we collect were made to be immediately copied. Pigments were cheap, rich, colorful and…weak. Boards were non acid free. You know it: once used, artworks were stored randomly if not thrown away. Back to pigments, the colors had to be vivid and the material cheap. Like a butterfly, an artwork had to live enough for its purpose. That’s why most of our illustrations have been made with acrylic. You could keep an original on your wall for years without noticing any change. The fact is that if you keep a picture of when you first receive it, once you see the difference it’s already too late.

I’m sorry. I personally keep my collection in a room with climate control and no windows, only LED light and I get the paintings out of conservation boxes only for limited periods.

A few years ago I’ve asked an artist about all this. Let me paste some excerpts from its reply:

"It's a good question and subject of discussion.  The short answer is, glass or no glass, it's definitely best to keep the paintings out of prolonged direct sunlight.
Regardless of brand of paint or type of paint, some pigments will fade if placed in direct sunlight.  These pigments are called "fugitive" pigments and it's just a matter of their chemical structure.  Most of the colors that both Boris and I use are made of heavier minerals and are less fugitive, so it's not as likely.  The tubes of paint we use are labeled in terms of how fugitive they are and we mostly stick to the ones that are less fugitive.
…
Still, it's always advised not to have any paintings in direct sunlight.  I've read that some pigments used in oil paint (which we use) like cadmium, are very lightfast (non-fugitive), but when used in acrylic paint they become very fugitive and will fade in sunlight."
Julie Bell

In conclusion: Know what you’ve got, the medium used and the board. Then use museum glass while keeping it in a room with no sun and no big change in temperature (the best is 18-24°C) and constant humidity (around 40-55%).

Another big advantage with museum glass is that it avoids reflections so you can enjoy your pieces of art at their best!
Check this side by side comparison (real pics of framed art):

[Ibrahim_UK 89]

It is fascinating to hear that Boris and Julie use specific types of paints and pigments that are less prone to fading. I expect nothing less from two of our most talented fantasy artists.

@NicYou give very sound advice, as Framing using Museum glass is not enough to protect your artwork from UV damage. The environment in which a painting is placed is just as important. Another point is the cheaper option of UV glass, which might seem like a good choice compared to the museum glass price.  As you would think, it offers UV protection and costs quite a lot cheaper. However, some UV glass provides only 70% protection compared to the higher spectrum of Museum glass, such as AR99, which offers 99%. 

So to add to your advice, make sure you know what type of glass and its UV rating, as not all UV or even Museum glass are created equally.