I am primarily active in the german wikipedia, were I do some edits and articles, when my times allows it.
When I was a child my grandfather gave me an old (and unfortunatly incomplete) small edition of Brehms Tierleben. I was fascinated by the drawings (kind of todays children are about dinosaurs). My professional carreer turned into a complete different direction, but I rediscovered the old volumes and now I try to scan the drawnings and paintings to have high quality pictures for the wikipedia.
The scans are made in full color (48 bit depth) and 600x600dpi, then scratches and occasional yellow tints are removed. After downsampling to 300x300dpi contrast, colour and gamma values are adjusted and the image is converted to grayscale and saved with annotation of caption, originator and source.