The slots for 6x4 photos are oversize which results in photos slipping when you try to put the back on before hanging the whole frame. In fact there is only one continuous back piece and therefore trying to keep the photos in place is virtually impossible. Disappointing design, really requires individual backs for each photo slot. After many hours fiddling to get back on without moving every photo, finally have it almost acceptable. Definitely would NOT order again unless they fix the backing problem !