These butterflies are from the margins of the Cordiforme Chansonnier, a book of vocal music from the late 1400s. Its red velvet covers form the shape of a single heart when closed, a double joined heart when opened. This lovely book, when opened, is barely wider than the span of my two hands.
And yes, these are cell phone grabs without a flash, from a morning in an archive with a facsimile. Bad photographer… distracted but enchanted researcher. 😀