How can I get a snug lid on hand-cut miter joints for a box without gaps?

[Nicholas63]

I’ve been trying to make a simple wooden keepsake box, but I can’t seem to get the lid to fit snugly without either sticking or having a visible gap. I’ve measured and cut everything carefully, but my hand-cut miter joints for the box corners might be throwing the whole square off.

[MichaelHW]

I had a similar box and the lid stuck when the wood swelled after a couple of days. I found it helpful to dry fit the parts without glue and test the lid by placing a thin strip under the edge to see where the tight spots were. Then I worked from the tight corner with a light pass of sanding on the lid edge.

[AdamSM]

Yeah those miter joints might be throwing the whole thing off more than you expect. If the corners are a hair off the lid will never sit flat. I once thought mine were square and found one corner was three pieces not quite true.

[Jason97]

I tried a quick check by laying the box on a flat surface and sliding a straight edge across the top to feel gaps. Then I cut tiny shavings off the inside edge of the lid lip and re checked. It was enough to let the lid close but not stay tight when it should.

[Scarlett71]

Could it be the real problem is not the joints but the lid seat being off by a hair when measured from inside to outside and maybe the lid needs a small relief in the center?