Is it necessary to use a sheet between a down comforter with a duvet cover and a fitted sheet on a bed?

Isn't it more customary to use a flat sheet between the fitted sheet and the comforter? Reads as if you are toasty warm.Is it necessary to use a sheet between a down comforter with a duvet cover and a fitted sheet on a bed?
Not necessesary, customary. To keep your skin and sweat off the duvet. You don't want to have to launder that frequently, it will be distorted and the finish weakend with excessive washings or worse--- Dry cleaning chemicals to sleep with!!Is it necessary to use a sheet between a down comforter with a duvet cover and a fitted sheet on a bed?
I don't know that it's necessary, but it keeps you from having to wrestle the cover off the duvet and wash it quite so often :-)
Ive always used a top sheet with a duvet even covered although have come across cheap bedsets that are just the fitted sheet a bedskirt and duvet cover so I guess to each their own.
You're better off using a flat sheet between the duvet. Think of how often you wash your sheets. Would you want to be removing the duvet cover and washing it like that all the time? I wouldn't!
I believe it is really a matter of your own personal preference.
I like my sheet between me and my comforter so I can kick the comforter off and I usually do.
No... it's a matter of personal choice! I choose not too use one either!