Artist created these images of double impossible tribars with airbrush.
Artist's site http://www.arnosoft.de/Grafix/airbrush/TriBars.htm
Click on thumbnails to see images in better quality.
 "Double tribar final")
 "Double tribar in the evening light")
 "Double tribar in space")
 "Double tribar with galaxies")
 "ArnoSoft logo"){kind=logo}
 "Impossible cube")