(1902 Zurich - 1988 ibid) "2 + 2 equal intertwined color rhythms on four white fields (red)". Original title: Color serigraphy / light cardboard, 1970. Verso signed, dated (difficult to read), numbered "H 67-100" and labeled "224 white lights". Sheet 60 cm x 60 cm. Silk screen in colors on thin cardboard, 1970. Hand-signed, indistinctly dated, numbered "H 67-100" and inscribed "224 white lights" on the reverse.