Just realized I've been over-sanding my butt joints for years because a homeowner in Charlotte pointed out the wavy light reflection. | Drywall Installers - Librear
Honestly, that "wavy light reflection" thing is such a perfect example. Tbh I see this everywhere now, where you need a simple trick to spot a hidden flaw. It's like checking if a picture is level by looking at it from the ground, you just need that different angle. Makes you wonder what other small mistakes we're all making because we never change our view.
Drywall taping is one of those things where you think it looks perfect until the sun hits it just right. I messed up a bathroom ceiling once because I was in a rush and didn't back-roll the compound enough, and the next morning that slanting light showed every single ridge. Now I always drag a trouble light along the wall at a low angle before I call it done, catches stuff my eyes miss completely.