I use my Paperwhite naked, without and cover or case. But I transport is in a neoprene case. I actually bought the case for my Fire HD8, which fits like a glove. Perfectly. The case would be a little too big, but usable, on the PaperWhite alone. But I nestle the PaperWhite next to the Fire tablet in the neoprene case because I always carry both of them in tandem.
https://evecase.com/collections/evec...ne-handle-case
My Fire tablet does have a cover and I nestle the PaperWhite with its screen facing the Fire's cover inside the neoprene case, so that adds additional protection. But I don't like using the PaperWhite with a cover - that just makes it too bulky and cumbersome. The only time you need protection is during transport anyway. I like the carrying handles on the neoprene (see picture at above link). This case fits the Fire HD8 (with cover) perfectly. And I mean perfectly. It is like it was designed specifically for this tablet.
Here's the cover I have on the Fire tablet:
https://www.amazon.com/dp/B01N2KGE68...ing=UTF8&psc=1