I know how to load shaders that I have downloaded (file > import...) But is there a way to permanently load them i.e. everytime you open maya even a new scene you can assign a custom shader to an object, without having to first load it?
Aaargh you coudl do this but you dont want to since thet would bloat all your maya files extra. This would slow all renderings down also.
Instead meka a new tab in hpershade and make it a disk based tab tab then put the shaders in that folder, if you must you could make a swatch for each shader and then you could just dragand drop the shaders on demand from within hypershade.
Thsiway tehy kload true but you never need to go hunting for them from disk.