For many publishers around the world 2015 was, fiscally speaking, an excellent year — a welcome boost in an otherwise uncertain decade. But this upturn had a perhaps surprising source: coloring books for grown-ups. What strange winds conspired to suddenly urge adults in their droves to take up colored pencils again? Whatever the reasons, sales rocketed: Nielsen logged sales of 12 million for the category in 2015, up from a measly 1 million the year before. In February 2016, with the craze still going strong, New York Academy of Medicine Library gave birth to a new initiative called Color Our Collections Week, a scholarly take on the coloring trend. Now in its third year, the campaign sees, on the first week of February, archives, special collections, and libraries take to social media with individual images and even entire books compiled from their holdings for the public to color. While these chosen works are all in the public domain, and so can technically include (in the US at least) works published up until 1924, the images in these coloring books more typically hail from the fifteenth through eighteenth centuries. And it is in these images — published in the centuries prior to the advent of color printing — that we can see a precedent for this seemingly modern fad. While it may seem like simply jumping on the adult coloring bandwagon, Color Our Collections Week, with its naturally historical focus, is actually tapping into (and shedding light on) a tradition much older.