I wouldn't have emulsion touching glass. Some images work well with the film border showing and some hand coated such as pt/pd with brush strokes visible. I prefer a cover mat and while not having a filed out negative carrier, if the print is dry mounted and signed on the board I use a window that is equal on the top and sides and longer on the bottom and allows the signature to show. I have gotten away from dry mounting as much as possible (if something happens to the board so goes the print) and sign on the back of the print and mount with archival corners. Those I have the window flush with the image. The pt/pd prints I do both ways depending on the image and some I mask so there are no brush strokes.