Ask HN: Why do rolled clothes use suitcase space more efficiently?

Or maybe they don’t. But they certainly appear to.

When rolling up clothes, you push some air out before you try closing your suitcase.

Also, I think packing the various parts into a container _feels_ a bit easier with rolled-up clothes than with folded ones (relatively flat, with slightly varying dimensions), at least partly because you’re a bit more inclined to compress them into a space.

The bin packing problem for rolled up clothes also may be easier than that for folded clothes, mathematically, but I can’t think of an argument as to why it would be.

I think it's mostly that you get a lot more mechanical advantage when tightly rolling than stacking flat, which allows a lot more air to be squeezed out. Once rolled, it's also easier to prevent it expanding: you just have to stop it unrolling, not by applying constant pressure to the whole surface. This is easier in smaller bags like backpacks actually, as compared to big hardshell cases, as it keeps the rolls fixed in place.

What gets tighter: wrapping tape around something or laying it along something?

I think part of it is they squish or can fit to shape differently than folded, meaning they can become sorta a hexagon sort of shape once compressed against eachother, and that’s the most efficient space filling shape. Also, like others said you don’t have to keep pressure on it to keep its state.

I think whatever extra tightness you get from rolling you lose in packing efficiency with other rolled things.