Sorry, not who you responded to, but flat is great on ceilings everywhere but a kitchen. There’s always a chance food gets splashed on the ceilings in a kitchen so it’s best to use semi-gloss or better so you can clean it.
I do semi-gloss in my bathrooms as well to keep moisture out of the walls as much as possible.
Flat in living areas is best in my opinion though for light refraction. Softer and more light gets refracted all around the room instead of just reflected straight from the light source.
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