His first designs date from 1893: vases, glass windows, book covers, later furniture, theatrical sets, and interior decorations.
The promotional poster for the sixth war bond (sechste Kriegsanleihe) was adorned with his painting Helft uns siegen!
[2] A soldier, his face darkened from the muck of the trenches, gazes beyond the viewer into No Man's Land with eyes that shine as if from an inward light.
This heroic image depicts the widespread contemporary belief that trench warfare would somehow be a morally cleansing experience.
[2] During the National Socialist period Erler's portraits of Adolf Hitler, Franz von Epp, and Wilhelm Frick were very remunerative.