Nozzle wear is one of those things that a lot of people talk about, but the discussion is usually pretty general. People will warn you that abrasive materials can wear your nozzle but that is usually where the conversation ends.

All materials you shove through your nozzle are abrasive to some degree. Some are worse than others, such as glow in the dark, or carbon/glass fiber. In this video from CNC kitchen, Stefan dives deep into nozzle wear, to educate us.

One thing I thought was interesting was that, before he even started messing with wear in the nozzle, he did some tests on different nozzle sizes using the same g-code, effectively simulating nozzle wear. This test alone was pretty interesting and gives clues on what to look for, to determine if your nozzle is getting worn.

There is a lot of stuff in this video to learn, from nozzle geometry, to filament chemistry, and even measurement methods. You should really go watch.