In May 2016, a pair of flats appeared at a pop-up market on Maiden Lane in San Francisco and sold out within days. They belonged to Rothy's, founded by Roth Martin and Stephen Hawthornthwaite, who had spent more than three years perfecting a 3D-knitting method before showing anyone a shoe. Online, the brand launched with two silhouettes, and the story spread from there.

What defines them is the build. Martin put it plainly: the upper is knit to shape, so it is seamless, then heat-set to keep its form. Add a foam insole and a rubber outsole, and you get a flat that feels like a sock and goes in the washing machine. Vogue, at launch, called them "the most environmentally friendly shoes on the planet" that "also happen to be the cutest."

So this is my Rothy's dupe edit, and I want to be clear about what that means. Nothing here comes from that brand. These are pieces from other labels that share the knit upper, the soft shape and the easy care, in the same spirit. Pointed flats come first. I would start with the Vivaia Aria 5 in beige with the black cap toe, a clean work-and-commute flat, or the Allbirds Breezer Point in dusty rose if you like your knits open and soft. The Tahari Antigua has a contrasting toe and heel panel, and the Skechers Cleo Bewitch has a tapered almond toe in stretch knit.

One practical tip for October: wear them with a pair of cropped trousers and a thin sock liner, and check the toe box before anything else. Pointed does not have to mean pinched, and the Vivaia Azura with its oversized bow is built with a wider toe box.

Mary Janes came back hard with the coquette trend, and the knit versions are the quiet end of it. A strap across the instep keeps a soft flat on your foot, and the knit keeps it light enough to fold into a tote. That is the defining idea behind the original's Mary Janes, and it is easy to find in other labels.

The square-toe Vivaia Margot has the right spirit, in black ribbed knit with a buckled strap, or in red with a silver buckle if you want one bright pair for fall. The Allbirds Breezer Mary Jane uses a cream open knit with two black elastic straps, so there is no buckle to fiddle with. The Keds Bliss Walk is an engineered knit with a simple strap, and the product page says to remove the footbed and use a cold, gentle cycle. The Naot Taranaki is a soft knit polyester upper with a sock-like fit.

Try this in the fitting room: fasten the strap on the middle hole and walk down a hallway. If your heel lifts, the strap is too far forward. Knit gives, but the strap should hold the heel.

Wear the black ones with gray tights and a plaid skirt, or with straight jeans rolled once. The FitFlop F-mode mixes knit and suede with a hook-and-loop strap, good for quick mornings.

What I would skip: any knit Mary Jane with a flat, thin footbed if you plan to walk all day.

A square toe changes the whole mood of a flat. It sits wider across the toes, and it reads more modern than a point. Business Insider suggested going for a square toe if you have wide feet, since "Rothy's toe boxes run narrow." That is a useful fit note for any look-alike: the toe shape matters as much as the knit.

The Vivaia Margot V-Cut flats come in a cream quilted knit with a tan toe cap, and in black ribbed knit as the lightweight Margot Walker. The Skechers Cleo Square Blissful Soul is a ribbed stretch-knit slip-on, offered in black and navy, which makes it the easiest one to wear with everything.

If you want a lighter feel, the mesh pairs lean more summery and slightly dressier. The Madewell Mylie in dark carob mesh has black piping, and the Sam Edelman Kasey is an open-weave knit in soft gold-tan with a low gold-tone heel. The Dolce Vita Arora is open mesh with a leather buckle strap, and the Franco Sarto Tatum has three buckled straps in blush.

Check the edge of the toe box. A good square toe has a clean, even line and no puckering where the upper meets the sole. Press the sides: you want give, not collapse.

For October, wear the navy Skechers with a gray wool skirt. What I would skip: open mesh in cold rain, since it is made for dry days.

Loafers are the hardest shoe to make soft, and knit is how it gets done. Wirecutter described the original brand's Penny Loafer as a classic slip-on with a padded heel, and the idea travels well: keep the classic shape, swap the stiff leather for a stretchy upper.

The Vivaia Silvie in taupe is a woven-knit square-toe penny loafer with a wide strap, and the brand says it is more breathable than classic leather loafers, with arch support. The Vivaia Ivana in brown sits on a lightweight, flexible sole. The Cole Haan Zerogrand Meritt is made in its Stitchlite knit, a navy upper with a white sole and leather strap. The Vaneli Quince has polished bit hardware on stretch knit, which is the detail that dresses it up, and the Tahari Andalusia has a braided strap in dark navy.

Pairing is simple. Wear the navy ones with cuffed jeans and a gray crewneck. Wear the Anne Klein Oakland in camel perforated knit with trousers and a cream blazer. The Keds Bliss Loafer and the Skechers Cleo Driver, with its scalloped collar, are the relaxed end of the group.

At the fitting stage, look at the heel. A loafer should hold your heel without a slide, so check the back for a firm cup or a padded collar.

What I would skip: a loafer with no footbed support if you are on your feet from morning to night.

Care is the whole point here. The original brand built its name on a shoe you can throw in the washing machine, and sneakers are where that pays off, since they are the pair that gets dirty first. Business Insider noted of the flats that keeping them in shape "is as easy as throwing them in the washing machine." Look for the same promise on the product page, and read the instructions.

The Allbirds Tree Runner in mist has a eucalyptus-fiber knit upper and is machine washable with air drying. The Allbirds Wool Runner in black with a cream sole is washable the same way. The Keds BlissWalk lace-up in light gray has Blissfoam cushioning, and the Saola Cannon Knit in black adds a cream sole and heel tab.

If you want no laces at all, the Born Mira has elastic laces and a cream platform sole, the Ryka Viv Ease has an elastic gore, and the Kizik Athens 2 is hands-free, with a heel spring that lets you step in. The FitFlop Super-Q in beige buff has decorative laces on a slip-on.

The test at home is easy: pull out the insole and look at the knit from the inside. A tight, even weave tends to hold its shape after washing, and a loose one can stretch.

Wear the Tree Runner with a plaid skirt and a knit sweater, or the Cannon with straight jeans. What I would skip: tossing any pair in the dryer, since air drying is what most of these ask for.

I would start with the shape, not the label. Pointed if you live in trousers, square if your toes need room, a strap if your heel slips, a loafer if the day is long. Then I would check the three things that sell the look: a seamless knit upper, a cushioned footbed and a flexible sole.

Then I would read the care tag. A flat that says wash on cold and air dry is doing the thing the original made famous, and that is the line I would look for first.

Back to Maiden Lane, 2016, and a table of flats that sold out in days. I would like to think the idea outlasted the pop-up. It is just a soft shoe that goes in the wash, and now there are plenty of ways to wear one. If you want to keep browsing, I also put together Ballet Flats vs Loafers vs Mary Janes and Maison Margiela Tabi Dupe.