What Is the Ideal Pair of Black Pants?

I need help figuring out which black pants are best. Lantern shape, too clownish? Peg legs, out of fashion? Accomplished women wearing black pants and blazers with a pop of color, like Elizabeth Warren and Angela Merkel, come to mind as looking fine for meetings but not so much for errands, concerts or dinner. Any suggestions for those of us trying to stay on trend gracefully? — Cheryl, Boston

First of all, black pants long ago transcended the very concept of trend: They are eternal. Like white T-shirts and white button-ups, they are part of the genetic makeup of a wardrobe, and like those two items — like DNA in general — they come in endless, often tiny, permutations. There may not be 50 shades of black, but there are 50 shapes of black pants. At least. It can be enough to give even the most stalwart among us option anxiety.

Indeed, one woman I used to know had almost an entire closet full of black pants, and when I expressed a bit of puzzlement about why she needed so many, she looked shocked. “Each of them is different!” she said.

She was an extreme case, but according to Vogue, every woman should own at least five pairs of black pants: tuxedo, denim, leather, leggings and slacks.

It’s possible, especially if you are accumulating them over a number of years, but in general it’s probably more practical to focus on just one pair. And to that end, it’s best to avoid the idea of what shape might be most of the moment, and stick to the silhouette that is both the most malleable and that never goes out of style.

Choose right and you could end up with a garment that works on the weekend, at work and at cocktails (even black tie), and needs only a different top or accessories to suit pretty much any context. As Angela Koh, T magazine’s fashion market editor, said when I asked why black pants were so key, it’s because they “rival the comfort of my sweatpants, yet look sleek.”

Think of the ideal pair of black pants as a primer for pretty much any outfit: the essential base on which you can build. That’s how Mesdames Warren and Merkel treat their black pants, and the truth is, with a sparkly top or a tuxedo jacket rather than their signature colored blazers, they’d look just fine at any concert hall or dinner.

To narrow things down a bit (no pun intended), I asked Nikki Ogunnaike, the senior digital director of Harper’s Bazaar, what style she wore. She admitted to having a few pairs of black pants in her closet, but said: “The ones I reach for the most are a bit high-waisted with a hem that hits right at the ankle. That way I can wear them with sneakers or heels — oftentimes, both in the same day according to what my schedule calls for.”

Look for a lightweight wool or twill fabric, as it works for both casual and more formal occasions. Ms. Koh suggested the best options were in “soft, good quality fabric and not too tight.”

Ms. Ogunnaike said that her all-time favorite pair of black pants were by Maison Kitsuné. If you are on a tighter budget, other good options are by J. Crew (these have a flatter front and a bit of stretch) and the Frankie Shop. Ms. Koh recommended this slightly more wide-leg style from Cos.

And as with jeans, I’m telling you: If you like a cut, don’t worry about what the trend forecasters say.

Your Style Questions, Answered

Every week on Open Thread, Vanessa will answer a reader’s fashion-related question, which you can send to her anytime via email or Twitter. Questions are edited and condensed.