"How come my jeans don't fit anymore?"

When I rotated my closet from summer to fall/winter, I tried on my jeans. If you had waited for me, you could have watched a film. I have pairs dedicated to walking, everyday life, going out. 

The surprise was not the quantity, but how they looked. Ideally, I'd like a neat fit like this Everlane pair (which I don't own), but about half of my stash looked lumpy and limp. I consider the mellow caress of   jeans one of life's great pleasures, and there I was, distinctly unsatisfied. 

Way-High jeans, Everlane

What le heck could go wrong? The problem begins before you even buy them, during manufacturing. A Bermuda Triangle of cloth, cut and construction lurks.

Cloth: Time was, all jeans were 100% cotton denim; then the miracle of stretch happened, but that typical 98/2 blend of denim/lycra trades comfort for bagging. In the past three years, more poly content has entered the mix, especially elastomultiester, a fibre used by brands like NYDJ to give Spanx-like stretchy support. Over time, though, elasticity erodes and there is a but a dim afterglow.

Cut: The fabric may not have been cut straight on the grain. Makers call these "twisters", and if the skew is subtle, they will slide by quality control. Washing off-grain jeans—and especially use of a dryer—encourages the seams to torque to the front, or you will see an odd dip on a hem that looked even. 

Construction: In lower-end jeans, the waistband is cut in a straight strip. Better jeans have contoured waistands, with sturdy stitching and facing. A tailor told me that when he makes mens' trousers, "the waistband is everything". The band is the scaffold from which the bell—the torso—hangs. When he tailors off-the-rack trousers, he often he often reinforces a flimsy waistband that is not literally lifting its weight.

In time, wear weakens and stresses the waistband, similar to a bra's band. What hugged you when bought home now gives you barely a glance.

Then there is our part: bodies change, and sometimes so imperceptibly we don't notice. When a half-inch shows up in a place we don't usually see, such as the rear upper thigh, the fit changes. While many women equate the loss of five pounds with an easier zip-up, they may also get a less precise fit in the seat.  

Even in a well-made pair, care affects how the jeans look. Fashion writer and editor Anne Slowey says putting your jeans in the dryer will cause them to "come out shapeless, lifeless and dull". At least jeans don't develop the shiny seat that beset my gabardine trousers. 

I donated three pairs, and am seeking a new source. Is anyone wearing Du/er? Their "performance denim" is a proprietary fabric that combines organic cotton with CoolMax poly (breathable, moisture-wicking) and 2% lycra for four-way stretch; the waistband is contoured, the seams triple-stitched. Looks good. 

Note to cold-weather readers: Du/er make a winter denim jean, which bonds a breathable water and windproof membrane to the denim, earning top marks from cold-weather cyclists.

Du/er Performance Denim Girlfriend jeans

Of course there is also the matter of style, but as someone who considers even contrast stitching to be visual clutter, the simpler the better, for me. 

I would appreciate hearing what jeans have won your heart, unless Balenciaga. Customer reviews on retailers' web sites are not very reliable, but I'll take your word for it!