Yes Mary, you have to be very careful with the framing, and especially with the positioning of the pictures etc. The autographed RVW ( the only photo with a signature) is on the dark side of the room, out of direct window light and not above any heating source or cold air from external door.
Folks may be interested in the following leaflets offering advice on
framing and maintaining prints, drawings and watecolours and ditto for
photos from
http://www.nationalarchives.gov.uk/preservation/advice/default.htmWe've got a painting which is based on the impressions of an artist with synaethesia of (I think) The dance interludes from bernstein's On the Town.