Flat is fine for the walls/ceiling, but your trim needs a sheen, typically semi-gloss.

I use B.M. and for a bit more durability I would choose Aura ( considered a matte finish) if I were looking for a “flat” finish.

I painted my entire home In Bears best flat off white paint, it is washable after it cures. I painted the doors and molding in Behr satin off white paint all with a 10% military discount ( I am a retired US Air Force Captain) from Home Depot. It is fantastic paint. Looks great❣️

I definitely prefer a flat finish for most walls and ceilings, except in the kitchen or bathroom. Even there, I tend to use satin rather than semigloss.

One exception, for me, was when I painted over cheap paneling that had no drywall under it (so not simple to remove). For that I thought that a satin finish would look better.

Flat makes me sad - it's a passive decor guest who does nothing for the room but suck up the light. I love a good eggshell/satin; it makes the walls and space look ethereal, bouncing light everywhere.

The only place I'll put flat is on the ceiling (and I paint my ceilings in the same color as my walls).

I'm not happy that I have to pay to not only get color on my wall that I'm not excited about but it's better to gray, but has to be flat sheen (builder choice). I'll put up with it for a while, but within a year I'm going to be testing paint chips.

Absolutely flat only for my walls and ceilings. I dislike ANY sheen on my walls...it looks cheap and unrefined to my eye. Flat is easier to touch up and is much better at concealing any imperfections in the walls.

Laughing "looks cheap and unrefined to my eye." Because flat paint elevates your standing?

I find it interesting that people are so negative in their judgment using cheap, unrefined, and gaudy. It's home interior paint for heavens sake not Versailles. I think some of you have been sniffing the paint too hard. Cluck cluck.

I have been using Matte for some time now and like the velvet finish without a sheen look that it provides. Before Matte became available I always specified flat ( well mostly, never anything above eggshell!) for walls. I don’t generally like shiny walls especially if the lighting is harsh and bounces around! It competes with the artwork and I find it distracting. There can be a harshness to very shiny walls but as a decorative finish they can be a wonderful thing! But... that’s something else altogether that usually involves high end spraying techniques and a lot of $$$$! Not at all the same as rolling semi- gloss on the wall!

All our walls and ceilings painted with BM Aura Matte finish paint, and all the base molding painted in BM Satin Finish (same color as each room’s walls). We even painted our fireplace wall with BM Aura Matte.