- He couched the painting in the nostalgic language of loss and remembrance that would become the true motor powering its celebrity and devoted one of only twelve of the book's full-page photogravures to illustrating it.
- A photogravure of the baptistery-chapel in 1897 shows the structure exactly as it stands today, but illustrations of the three large mosaics in the same publication differ significantly from the finished works.
- Mills may have paid a record price, but Goupil still owned the copyright, which enabled him to reproduce the composition again in 1877 as a photogravure.
- By the 1880s, and the last two years of Darwin's life, virtually all that the public saw in published photographs and photogravures were his beard, his hat, and his eyes.
- Traditionally, photogravures have been small prints (8 by 10 inches or smaller), with a quality level higher than that of offset reproduction but lower than that of fine art prints.