Willibald Demmel ( 1914 - 1989 ) was a German painter. Willibald Demmel s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 497.72 USD for Stillleben mit Knoblauch und Kupferkanne. in 2006 to 912.48 USD for Negerin in 2006 , based on the size and medium of the artwork.