Ballet flat, Mary Jane and slingback: what actually changes
A ballet flat is the closed shoe with a flat sole, no heel and no fastening, with a topline that leaves the instep exposed. It is the starting shape: a Mary Jane adds a strap across the instep, a slingback replaces the closed heel with a strap behind the ankle. All three are on this page, and the difference between them is not aesthetic.
The strap is what keeps the shoe on the foot when the sole is flat. A ballet flat without a strap stays on through friction and through the shape of the topline, and on a narrow foot it tends to slip off when you walk fast; a Mary Jane or a slingback solve the problem at the root. Anyone who has already lost a ballet flat on the stairs should change the strap, not the size.
The materials on this page are smooth leather, nappa, suede, patent leather and velvet, and they age in different ways. Nappa is the softest and moulds to the foot within a few days; smooth leather is more structured and holds its shape better; patent leather barely stretches at all, so it has to be bought in the right size from the start; suede and velvet are the most vulnerable to water and rubbing and need a protector before you go out.
The weak point of a flat shoe is not the upper, it is the insole. A flat, thin sole passes the whole impact of each step straight to the heel, which is why some ballet flats become tiring after two hours. A padded insole, even a few millimetres thick, and a rubber sole with a little flex change the result over a full day: they are worth checking before the colour.
On flat shoes the size is easier to get wrong, because there is no lacing to compensate. It is best to try them at the end of the day and, between two sizes, to consider half a size down on nappa models, which stretch, and half a size up on patent ones, which do not. For a flat shoe closed over the instep look at the women's loafers; for an elastic fit with no strap, the women's slip-ons.
