What am i missing to get a snug lid on a wooden keepsake box?

[Layla.L]

I've been trying to make a simple wooden keepsake box, but I can't get the lid to fit snugly without sanding it so much the gap becomes obvious. My miter joints are okay, but this final step of getting a perfect, seamless closure is really frustrating me.

[Ella33]

I had a similar problem once. The lid would catch even though the miters looked fine because the top panel wasn't perfectly square after glue up. I measured at several points and found one corner a hair off. I shaved a tiny amount with a block plane and let it dry under a light clamp. It helped, but I had to re-check thickness a few times.

[JonathanS]

I chased a seamless seam for days and finally admitted I might be chasing a moving target. Humidity made the lid swell, then shrink, and a perfect fit was elusive. I stopped sanding in circles and left it a bit looser, since it opened and closed fine.

[MichaelFL]

Have you checked if the lid is actually longer than the box opening by a hair and binding on one corner? What if the problem is the bottom or the inner rabbet not sitting flat?

[DonaldT]

One time I drifted away from the project, cleaned the workbench, and came back with a clearer head. I found the lid was rubbing because I’d trimmed the wrong edge and the piece was slightly skewed; rechecking with a straightedge helped. Not a tidy fix, but it saved more wood.