Best Silk Pajamas

Pajama is a borrowed word. Merriam-Webster traces it to the Hindi and Urdu pājāma, from the Persian words for leg and garment, and its first use in English, in the early 1800s, simply meant loose trousers. Europeans living in Asia took up both the trousers and the name, and from about 1870, the South China Morning Post notes, pyjamas steadily replaced the traditional nightdress as men's sleepwear in England. Somewhere along the way the leg garment became the thing we sleep in, and silk became the version people keep for best.

I redid this edit with one rule: every piece is actually silk. No satin that only looks like silk, no cotton with a silk trim, no polyester charmeuse. That cut a lot. What is left is long button-front sets, short sets for warm rooms, camis and sleep shorts, and a last group of robes, slips and pieces you can mix.

Silk is weighed in momme, a Japanese unit where one momme is about 4.34 grams per square meter. Sleepwear usually sits between 16 and 22, and a higher number means a heavier, more opaque cloth. Washable silk is the other thing to look for if hand washing is not going to happen in your house. Lunya built its business on it after Ashley Merrill launched the brand in November 2014, and the Eberjey Inez pieces below are washable too.

My test before buying: read the care label first, then the size chart. A silk set you are scared to wash will live in a drawer.

Olivia von Halle launched her label at London Fashion Week in 2011 with a single silk pajama, the Lila, and the brand says the idea came from the lounging pajamas Coco Chanel and her friends wore in the 1920s. The Lila long set is here, and it is the one I would point to if you want to see what a proper silk pajama looks like: a piped shirt, a long wide leg and enough cloth to move in. The Yves, Tilda, Zebedee and Elvira are the same idea in different moods, from bold print to a long camisole with trousers.

Petite Plume does the classic button-front in mulberry silk, in white, in two Panthère prints and as the Celine shirt with wide leg trousers. Eberjey's Inez long set is washable silk, and so are the four Lunya sets: the High Rise set with a short sleeve shirt, the Long Sleeve Pant Set and two Bias Cami Pant Sets, in lilac and in a deep blue. Fleur du Mal's Barolo set is silk jacquard, the dressiest thing in the row. Toteme's piped top and trousers and La DoubleJ's shirt and pants are the ones I would wear to a late breakfast outside. If you only want the bottom half, Bondi Born's Cannes pant pairs with any cami further down.

A fit test: sit cross-legged in the trousers. If the seat pulls or the hem rides above your ankle, size up.

What I would skip: a busy print as your only pair. Plain silk gets worn more.

A short set is what I actually sleep in from May to September. The shape matters more than with a long set, because a short that rides up or a top that twists will wake you. Lunya has the most options here, all in its washable silk: button up shirts with shorts in a brown dot, a pale stripe and butter yellow, a piped long sleeve version, a plain white one, tee and short sets in pink and in white, and a tee pajama set in a wisteria stripe. Long sleeves with shorts sounds odd until you try it in a room with the air conditioning on.

Petite Plume's pink stripe and Regatta Royale sets are the traditional piped versions, its Panthère de Nuit short set matches the long one, and Olivia von Halle's Ingo is the brand's short set. Eberjey's Inez comes in a short too, if you liked the long one. Fleur du Mal sells its PJ top and short separately, both 93 percent silk with 7 percent elastane, which gives them a little stretch the others do not have. Journelle's Celine shortie is the smallest piece in the group and pairs with the Celine cami below.

A practical test: lie on your side in the shorts. If the leg opening gapes or the waistband digs, it is the wrong cut for sleeping.

What I would skip: pale shorts in a thin silk if you dislike anything sheer.

For a hot room, a cami and a pair of silk shorts beats any set with sleeves. Most of this group is sold as separates, so you can buy the cami in one size and the short in another, which is the main reason I like them.

Eaves makes the Loretta cami and short as a pair, plus the Roux short in chocolate brown. Bondi Born's Cannes camisole and short come in a forest stripe that matches the Cannes pant in the long group. Tularosa's Lio cami and short are the plainest, and DONNI.'s lace tap shorts, in dill and in shitake, are the prettiest. Comme Si's La Boxer Classica is a silk boxer short, and I would wear it with the Journelle Celine cami or the fleur du mal Juliet lace cami. If you would rather not choose, Petite Plume's lace cami short set, the SKIMS silk lace garter cami and short set and Lunya's knicker and tulip back sets come already matched.

A strap test: raise both arms over your head. If the cami slides or the straps dig, adjust them or size up before you sleep in it.

What I would skip: a lace heavy cami if you sleep on your stomach. Lace on silk can scratch.

A robe is the piece that makes silk pajamas feel like a habit rather than a costume. Eberjey's Inez robe matches the Inez sets above, and Petite Plume's Panthère de Nuit robe matches the printed set, so you can buy the pair once and stop thinking about it. Lunya's washable silk robe is the one I would choose for every day, because it goes in the machine.

GINIA has four pieces here: the Aurora silk chemise, a short wrap gown with a lace trimmed robe, a wrap gown robe and a lace robe. Journelle's Celine slip, in noir, goes with the Celine cami and shortie above. The rest are separates for mixing: Toteme's monogram silk culottes, the Eaves Loretta pants, Helsa's silk charmeuse pajama shirt in fudge and Uwila Warrior's silk lace sleep short. The Helsa shirt over the Toteme culottes is the outfit I would put together first.

A length test for a robe: tie it and sit down. If it falls open above the knee, choose a longer one.

What I would skip: a robe in a heavier fabric than your pajamas. It drags on the silk underneath.

I would keep a silk drawer small. One long set, one short set, a cami and short, and a robe cover more nights than a dozen pieces, and they make laundry less theatrical. Wash silk cool and inside out, by hand or on a delicate cycle if the label says washable, and dry it flat out of direct sun. Iron it on the lowest setting from the back, or hang it in the bathroom while you shower. The best set is the one that gets worn and washed, not kept for a guest room weekend. Choose the silk you will actually sleep in.