Why 0.40mm?

Quantum mechanics makes me look at things in new ways. A recent browse through current topics on 3D printing revealed some pundits are questioning how in FDM printers, did 0.40mm nozzle become so dominate with the 1.75mm filament.

I am not going to explore the reasons here. Best to say, for the typical size prints made by hobbyist, it is a very good choice. It works very well.

That is not saying it is the one and only good option.