Preferably satin. But if you prefer the more matte appearance then you could customize with sheens: Satin for colors that qualify as slightly above mid-value and below. Eggshell for darker color - because as a general rule darker colors will show as if they have more sheen than lighter colors. Best quality 100% acrylic satin exterior does indeed clean, wear, and look better long-term. I don't like shiny either. Much prefer matte finishes - but that's interior. When it comes to exterior, sometimes you gotta put function before aesthetics and gloss levels might be one of those times. Personally, satin exterior doesn't bother me near as much as it does interior. It's just doesn't have the same affect and isn't as significant or noticeable, IMO. Much more gloss than a satin -- like a semi for exterior on body or trim -- isn't where folks wanna go either. Satin or an eggshell that's heavy on the sheen are good choices.

I have never, ever used flat for any exterior work, satin at the very least

We have just finished replacing Rotten wood and painting one side of our sunroom (trim,door and hardiplank). We meant to purchase satin for the siding and semigloss for the door/trim but somehow I ended up with satin for both. I am Out of trim paint but still have a second set of French doors and some window trim to paint. Should I buy semigloss and repaint the door that I’ve finished or just carry on with the satin? before: After:

You bet it will…I always paint my exterior in a low sheen. It weathers over time, but, in the meantime, it seems resistant to the weather wear and hoses down great after pollen season.