Factum II looks almost identical to Factum I, hanging next to it, but what this pair of works shows is actually the uniqueness of any given work of art. Just as the days evoked by the calendar pages glued to the canvas may follow each other but are never the same, two brushmarks may look alike but are always different. During a period when spontaneous invention was a valued principle in painting, Rauschenberg worked on Factum I and Factum II simultaneously, shuttling back and forth, detail by detail, between the two works, playing the pictorial game of making them match. The irony, as he surely well knew, was that ultimately each work would retain its stubborn uniqueness. As Rauschenberg has said, "The things all paintings have in common are paint, and color, and some means of application. With that standard you can make any two pictures appear either alike or different. I don't think whether they are alike or different is really very interesting."