I assume that you are speaking of a Serigraph (silk screen print process). These being a paper art form, of course would benefit from matting. Conservation quality board in front of the artwork creating a Window mat, and conservation quality mounting board behind.

Conservation filtering glass would be another option and really is a judgement call by the owner. UV damage from light is one of the biggest factors in protecting framed items of value. On the other hand, Serigraphs are made with very colorfast inks, and are the most fade resistant of original graphics.

You might consider the value of the artwork. Please reply if you have further questions.