How to achieve ceiling recess LED strip

[BirgitS]

That actually looks interesting. But it's in the bathroom ceiling. Thinking about moisture and such. How would you make it "sealed" where the beam is?

There is no waterproofing layer in the ceiling, so it doesn't need to be sealed. However, it is good if the material can withstand a bit of humid air, so if you're worried about the molding, paint it with wet room paint.

The molding is mostly for appearance and to compensate for the lack of light from the spotlights where there's a sloped ceiling. It's a relatively large area with a sloped ceiling, and there's a risk it could be a bit dark there.

With such a construction, regardless of how it's technically solved, it will mainly be decorative light, I think. It probably won't work very well as cleaning light, etc., regardless of strength, as it will likely be a narrow beam.