Wash is the fastest way to change how dressed up a pair of jeans looks, and it does more work than the cut. A dark indigo or true black reads closest to a trouser, a mid blue is the neutral middle, and ecru or white sits at the casual end while somehow also being the hardest to wear badly. The thing nobody mentions is that darker washes bleed, so a new pair of black jeans will mark a pale sofa and a light bag for the first few wears. Below, the ecru and pale washes, the mid blues, and the blacks and dark rinses. Finish matters as much as shade. Whiskering, sanding and printed fades are what make a dark pair read as casual even when the base colour is nearly black, so if you want denim that passes as a trouser, look for a clean leg with no contrast at all.

Ecru, white and the palest washes are the ones I reach for most in warm months. Opacity is the only real risk, and a heavier fabric solves it entirely. Opacity is the only real risk with pale denim, and fabric weight solves it entirely. Anything around eleven ounces or heavier will be opaque; a light summer weight will not, whatever the colour. A little texture in the weave helps, because a slub or a twill catches light where a flat smooth surface lets it straight through.

Mid blue and vintage washes are the ones that go with everything, and the ones where fading is a feature. A wash with real contrast at the seams looks worn in rather than printed. Mid blue is where fading becomes a feature rather than a problem. A wash with real variation, lighter at the thigh and knee and darker at the seams, looks like it has been worn rather than printed. Rigid mid blue denim is the category where a pair genuinely improves over years, because the fade follows how you actually move.

Black and dark rinses are the closest denim gets to tailoring. Buy these in the cleanest finish you can find, with no whiskering, and they will pass in places jeans usually do not. For the cleanest possible finish, look for what is sold as a rinse rather than a wash, which means the fabric has had the loose dye removed and nothing else done to it. That is the version that reads closest to tailoring. Expect the first few wears to transfer colour, and expect the depth of the black to soften slightly after the first wash and then hold.

NYDJ covers the full range of washes in the same few cuts, which makes it genuinely useful for working out what you want before you spend more. The lift and tuck construction is not marketing; the panelling is really there. Having the same cuts available across the full range of washes is more useful than it sounds, because it lets you separate the two decisions rather than compromising on one to get the other. The construction through the waistband and front is genuinely different from a standard five pocket.

A wider spread of washes, if you would rather compare across brands. A wider spread of washes across brands to finish, for comparing shade rather than cut. If you already know which leg shape you want, this is the fastest way to find it in the colour that is actually missing from your wardrobe.

Wash new dark denim on its own, cold, inside out, once, before you wear it anywhere near a cream chair. That single wash takes most of the excess dye out and costs you almost nothing in colour. After that, the less you wash denim the longer the colour lasts, and airing a pair overnight does more than most people expect. I go months between washes on my darkest pair and it still reads black.