Does a photograph left uncovered (i.e. on a wall with no glass over it) fade?

[COAFO]

I want to mount a photo on a decorated canvas - does an uncovered photo fade, even if its not in direct sunlight? Thanks!

Yes it will fade but the rate will depend on the amount of light and the quality of the print.

does glass, like in a traditional photo frame, stop fading?

To an extent, yes. Well it slows the rate of fading down but ultimately light is the enemy.