Take a look at this very rough draft of the cover for Thomas Martin's Circle Of The Mechanical Arts
Notice the section of the Coach Making plate? It's in color, isn't it? Why, you might ask, if I am printing the book on color presses to maximize the legibility of the grayscale images, would I have inserted grayscale images for the 39 plates instead of color?
Because, I might answer, I assembled the book content months and months prior to the availability of Lightning Source standard color printing, an affordable option to their previous premium only color printing selection. During the following many, many, many months I was researching who Thomas Martin was, to no avail of course.
While working on the cover, I had my DUH moment and realized that the plates should all be the full color versions.
DUH moment over, I'll fix up the book with the color plates and get on with publishing it.
Till next, Gary