On a trip to Venice to acquire art for the Royal Palace in Madrid, the great Italophile King Charles III of Spain was presented with a pair of eyeglasses by his royal physician. Venetian glass, long renowned for its legendary quality, had lately fallen into a period of decline, owing to competition from the glassworks of Habsburg Bohemia. Privately, Charles noted the chromatic impurities of the lenses — one was slightly blue, the other slightly red — for which his physician adroitly improvised an explanation that appealed to Charles’s piety: the blue symbolized the Virgin Mary, the red, the blood of Christ.

Still, on a subsequent visit to the Real Fábrica de Tapices in Madrid, Charles found that certain arabesque patterns woven in blue and red thread seemed to dazzle the eyes. From this, his physician deduced an interesting principle: that images colored to match individual lenses could create the illusion of depth perception. This was the dawn of stereoscopy, the phenomenon that would ultimately lead to 3-d movies.

A collection of duotone engravings was presented to the king on the occasion of his fiftieth birthday, which were confounding to the assembled, but which Charles alone experienced in three dimensions. So delighted was the king that the Imprenta Real was directed to begin the production of 3-d books, for which special printing presses with both red and blue beds were developed. The immaculate condition of these beautiful stereoscopic presses suggests that they saw little use, and the near-total absence of eighteenth century 3-d books implies that Charles’s fickle attentions were soon drawn elsewhere.

Published January 18, 2023. Copyright © 2023 Jonathan Hoefler.