Spanish to English Art/Literary Printing & Publishing

I understand that this usually refers to a threesome that divides a task. but here I am not sure. Seems more like what they produced (in this case a limited edition of three books, each with its own title (Pajaro, Hoja, Viento):

Aquellos tres ejemplares especiales y su denominación podemos decir que son una influencia del mundo de la bibliofilia. En general, la terna era repartida entre autor, impresor e ilustrador. En este caso, mi padre recibió el ejemplar Hoja...


(the writer is the daughter of the printer, who did an original etching for the edition)

Thanks!