a light-sensitive document of a lighthouse that is in the sunlight
In this case, this blueprint that was left too long in the sun. It is now exhibited in a room full of indirect sunlight, although it is not facing the window. This is not a good choice. A copy in the room would be better than having the original there on display to further speed its deterioration. I thought this being a light-sensitive document of a lighthouse that is in the sunlight would be an interesting Friday comment on archival architectural materials.