(i) pencil and coloured pencil on paper
(ii) marker and pencil on paper
(iii) mixed media on paper
(iv) marker on paper, mounted to card

(i) signed and dated 'Trockel 85' lower edge
(ii) titled '"a b c d e f"' upper edge and inscribed 'Klöppelbrief zum Einsatz' lower edge
(iii) signed and dated 'Trockel 86' on the reverse
(iv) titled '"VORLAGE 1"' lower left; further signed and dated 'Trockel 86' on the reverse

(i) 21 x 15 cm (8 1/4 x 5 7/8 in.)
(ii) 22.5 x 17.5 cm (8 7/8 x 6 7/8 in.)
(iii) 29.5 x 21 cm (11 5/8 x 8 1/4 in.)
(iv) 31.5 x 22 cm (12 3/8 x 8 5/8 in.)

(i) Executed in 1985.
(ii-iv) Executed in 1986.