Frederick McCubbin.
It was painted in 1904
A panel is generally a unit that makes up a multi-piece painting. If the painting has two panels, it is called a diptych. Three panels would make it a triptych. One of the reasons they may be called panels is that they may predate the popular use of stretched canvas and be painted upon wood panels.
SO they don't rust.
No, he painted on wood panels.
Yes, they can.
P=73/3
p=63/3
panels
If they are PV panels or heat pipe panels, they are not painted at all, paint would stop them working. Only a simple hot water radiator panel would be painted black and you would do this because the colour black absorbs all solar radiation, other colours reflect some of the suns energy.
The total width of the triptych being 45 inches, each of the thre panels has a width of 15 inches.
There are three syllables in the word "Pioneer" (pi-o-neer).
Wood panels withstand time, and the kind of canvas used today had not yet been invented.