[shackley]

The Large Transparancy photographs as used
in the advetising business( the ones that have lights behind ). Attach to a white opacque board ( to allow sun light through ) then use as shutters / secondary glazing on the outside of windows that do not have attractive views. Photos of sea views, beaches,forests , mountains , famous sites ,anything to improve the ambience of the room .

Reward: let me know if it works

[Steve]

I cannot see how this would leave even nearly as much sunlight through as a clear window. Maybe I'm not aware of the transparent photographs used in the advertising business?