Niello prints, like the art of engraving as a whole, have their origin in the workshops of gold- and silversmiths. The word stems from the Latin nigellum and refers to a sulphur and metal compound used mainly in 15th century Florence and Bologna to decorate engraved silver plates. Heated and poured onto a finely engraved plate, the liquid alloy would fill the lines and harden into a black enamel-like substance. On polishing the surface of the plate, the black niello creates a contrast to the shining precious metal of the plate.
Before the niello was melted onto the plate, impressions on paper could be taken in order to examine the engraved design before completing the work, or to keep a record of the finished work. However, we do not known to what degree these impressions on paper were considered mere records of fine metalworks or were appreciated as works of art in their own right.
We known as little about the makers of niello prints as we know about their uses. One of the only niellists known to us, Peregino da Cesena (active circa 1490-1520), was also the only one to mark his plates with his monogram or name. However, his marks do not appear in mirror script on the prints, implying that they were meant to be readable from the print taken from the plate, and not the plate itself. Niello prints stand at a crucial turning point when intaglio printmaking emancipated itself from the production of precious metal objects.
Genuine niello prints from the late 15th century are of the greatest rarity and most, such as the present example, only exist in unique impressions. In style, subject and size, the present Portrait of a Boy in a Calotte closely corresponds to a Jeune homme coiffé d'une calotte (Blum 135) in the Louvre from the Durazzo Collection. The print has exactly the same width as the present example and also shows a boy in profile to the right, with long-flowing hair and calotte and with thin white clouds in the dark sky above. Blum describes it as 15th century Florentine School. The other closely related print has - remarkably - survived in two impressions: a slightly damaged one in the British Museum (Hind 247; Bartsch XXIV, 19), previously from the collections Sykes and Ottley, and one in the Louvre (Blum 168), again from the Durazzo Collection. It depicts a boy and a girl in profile facing each other, with a vase in between, a landscape in the background and thin white clouds above. Hind believed this double portrait to be probably of Florentine origin, while Blum thought Ferrarese. Whatever the case, in expression and treatment, down to the use of the lines to describe the faces, the hair and the clouds, this print resembles the present portrait so closely one is tempted to speculate that they might be by the same hand.