What’s the difference between glass and plexi? What about UV protection?

What’s the difference between glass and plexi? What about UV protection?

 

    

Glass is familiar, cheaper and can be cleaned with almost anything. It also has a slight olive tint and if it breaks you usually end up with damaged art. Plexiglass has almost no color tint, is lighter, has about 85% U.V. protection and is very difficult to break. It needs to be cleaned with a soft cloth and non-ammonia cleaner and should not be used on pastel or charcoal drawings without significant spacing. Both glass and plexi are available with 98% U.V. protection. This version of both adds a slight yellowish tint.