Hannes Portmann ( 1927 - ) is a Swiss painter. Hannes Portmann s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 102.94 USD for Komposition m. Clowns u. Papagei in 2004 to 1291.22 USD for Verbündete in 2017 , based on the size and medium of the artwork.