What materials were used to make the original print Flowers (1970) by Andy Warhol?

Flowers (1 purple, 1 yellow, 2 pink)

What materials were used to make the original print Flowers (1970) by Andy Warhol?
He made prints of a photograph and then painted with washes of dye over the print. More info here:





http://gallerywarhol.com/andy-warhol-flo...