Why thick seams dry last

Short answer: In a seam, two or three layers of fabric lie on top of each other. More water gathers in the same spot and there is less surface to evaporate from, which is why seams and waistbands are the last part of a garment to dry.

More fabric, less surface

Three layers of fabric in a seam hold three times as much water as one layer. The surface, though, is only slightly larger, so evaporation is slow. The water sits between the layers, where air has trouble reaching, and it takes time to work its way out to the edge.

The thread holds water too

The sewing thread is tightly spun and dense. It lets go of water more slowly than the surrounding knit, and it lies exactly in the seam. That makes the seam the place with the most fabric, the most thread and the least air, and that combination dries slowly. See bamboo night shorts for women.

Why a garment feels dry before it is

The flat areas dry first, and a garment can feel dry while waistbands, edges and seams are still damp. The hand feels the free fabric, which is dry, and easily skips the thick spots. So you may put away a piece that is not quite finished. See bamboo bodystocking and bamboo undershirt for women.

How do I check that it is fully dry

Press on the waistband and on the seam under the arm. If they are dry, the rest is too. Check the thickest spots first, because they dry last, and if they are dry you need not guess about the rest. It takes seconds and tells you more than feeling the open fabric.

Can damp seams cause odour

Yes. Never fold clothes while the seams are still damp. Moisture sealed inside a folded garment stays put, and then the clothes start to smell stale. If in doubt, let the piece hang a little longer before it goes in the drawer.

Does turning the garment help

Yes. Turn it inside out for the last half hour and the seams dry faster. The thick spots then lie free in the air instead of hidden inside, and air reaches where most water sits. It is a simple habit that makes a clear difference for waistbands and seams.

How to hang to help the seams

Hang the garment so seams and waistbands do not lie doubled or squeezed together. Avoid pinching them with pegs, where the thick spots get pressed flat. Let them hang free and give the piece room from its neighbours so air can circulate.

Allow for it when planning drying

Expect seams and waistbands to take longer than the rest of the garment. Plan so you do not need it straight away, and leave it hanging until the next day if in doubt. That avoids damp edges against the skin, and the garment is pleasant to put on.