Size is one thing, the way the beam is located or utilized can telegraph that it is fake. A true structural beam rarely looks fake. A fake beam does not look real unless it mocks a real beam in every way. Make it look like it is supporting whatever is above it, and not like a bump on the ceiling.

Yes - definitely. The placement looks like a support beam, just trying to decide actual size of the beam (8wx8d) vs (8w x 4d) to look best in the room.
Thanks!

Painted, stained, rustic ...? What material and finish is the ceiling?

How the beam itself looks will impact how it looks in the space?

8x8

8x4

And I prefer beams that do not simply hit a wall but rather another, larger beam. This is more like an actual timber framed house would look.

Wow these pictures are great - thank you so much! We were thinking stained beams.. lightly distressed… the ceiling is white drywall. We do plan to have some stone on fireplace with built ins next to them. The mantle will likely match the beam color.

I think I like the look of 8wx4d better but don’t want it to look too whimpy based on room size/ceiling height ☺️

What size do you think this picture is?