The original page from Young People's Natural History was scanned & printed archivally, then I began adding thin layers of paint (Golden Fluid Acrylic, sometimes with a touch of Golden Open Medium).
Between the first & second scans of the painting, I added a wash of green to the image area. Unfortunately in doing so I lost all the detail from the original zebras, which I'd hoped to have faintly showing through in the final. But so it goes!
The final art is on my Oddments & Curiosities blog.