Das schräge U

WALTER DEXEL (1890-1973) Das schräge U signed 'W. DEXEL' (lower right); inscribed 'VORSICHT! HINTERGLASBILD W DEXEL 28 DAS SCHRÄGE "U"' (on the reverse) oil on glass 12 ¼ x 12 ¼ in. (31 x 31 cm.) Painted in 1928