Pantyhose and the Shortened Hemline

I think this is one of the most underrated construction stories in the entire decade, precisely because it's an undergarment rather than anything visible. Pantyhose - a single knitted garment combining a brief-like underwear layer and full-leg stockings into one continuous piece, held up at the waist rather than by a separate garter belt - had actually existed in a rough commercial form since the very end of the 1950s, but it's the rising hemline of the mid-1960s that turns it from a minor convenience item into something close to a practical necessity.

The problem it solved is a genuinely mechanical one. Traditional stockings were held up by a garter belt or girdle sitting at or above the natural waist, with visible clips, hardware, and a garment edge that a longer hemline comfortably concealed. Shorten that hemline to well above the knee, as the mini skirt did through the middle of the decade, and all of that hardware becomes visible or at serious risk of showing with any movement at all - bending, sitting, or simply a gust of wind. Pantyhose removes the problem at its source by eliminating the garter mechanism entirely, replacing it with a single stretch-knit garment that stays in place on its own and leaves nothing structural to peek out from under a dramatically shortened skirt.

I'd call this a genuine case of undergarment engineering following, rather than leading, a change in the visible silhouette - the mod silhouette couldn't have spread as fast or as comfortably as it did into ordinary daily wear without this specific fix underneath it, even though almost nobody credits pantyhose when they talk about the mini skirt's rise. That's a pattern worth watching for across this whole project: a dramatic, headline-grabbing change in outer silhouette is very often quietly dependent on a far less glamorous fix happening in the layer nobody sees.