JSK, OP, SK: What Each Lolita Garment Actually Is
Lolita listings are written in abbreviations that nobody explains, because within the scene they are assumed. They are not jargon for its own sake: each one names a specific garment with specific consequences for what else you need and how the size behaves.
JSK — jumperskirt
A JSK is a sleeveless dress, most often with straps or a bib front, designed to be worn over a blouse. It is the most flexible piece in the wardrobe because the blouse underneath changes the season and the register: a short-sleeved cotton blouse in summer, a high-necked one in winter, or a knit for something casual. Because the bodice is sleeveless it also fits a wider range of shoulders than an OP, which is why it is usually the safest first dress to buy.
OP — one piece
An OP is a complete dress with sleeves, worn on its own. It needs nothing over or under it besides a petticoat, which makes it the easiest thing to wear and the least flexible thing to own — one OP is one look. Sleeves also make fit less forgiving: the shoulder and upper-arm measurements matter in a way they never do on a JSK, and they are the measurements most often omitted from a chart. Check them before ordering.
SK — skirt
An SK is exactly what it sounds like, and it is the piece that does the most work per unit of money. A skirt pairs with blouses, cut-sew tops, bustiers and knitwear you may already own, so it multiplies rather than adds. It also solves a fit problem: a waist measurement is far easier to match than a bust measurement, and many skirts are fully shirred at the back. If a bodice measurement is borderline on every dress you like, buy the skirt.
Blouses, cut-sews and bustiers
A blouse is the layer under a JSK or with an SK, and it is where a coordinate quietly succeeds or fails: the lace and collar have to agree with the main piece. A cut-sew is the knit equivalent, softer and more casual. A bustier or corset top is structured and boned, worn over a blouse or on its own with a skirt. Boning is the one construction that will not yield — a bustier has to fit at its stated measurement, with no give to borrow.
Salopette, JSK and the ones that blur
A salopette is a pinafore-style piece, usually with wider straps and a less formal cut, sitting between a JSK and casual wear. You will also see "full set" or "set", which means the listing includes more than one garment — often dress plus headwear, sometimes dress plus blouse plus accessories — and the price reflects it. Read the set contents before comparing prices between two listings, because a set and a single piece are not the same purchase.
Which to buy first
If you want one purchase to be wearable immediately, an OP in your measurements is the shortest path. If you want the wardrobe to grow, a JSK plus one good blouse gives you more outfits from the second purchase onward. If your measurements sit awkwardly against the charts, start with a skirt, which is the most forgiving thing to fit and the easiest to coordinate with clothes you already own. Whatever you choose, a petticoat is not optional — the silhouette is the style, and without it every one of these garments reads as an ordinary dress.