If you search for "Corset" on Ebay, the vast majority of the results will not actually be corsets at all. So how do you know that what you're bidding on is actually what you want? To the trained eye, the imitations stick out like a sore thumb but so many things get described as corsets on the high street it's easy for the casual buyer to be fooled. Here are some questions you should ask yourself:
What are you actually looking for?
When you say you want a "corset", is what you have in mind a corset at all? A corset is a very rigidly boned item designed to bring in the waist, usually by about 4" and are not cheap. If that surprises you and you want something more comfortable, you probably want a basque, bustier or gothic top. Bustiers are often very pretty imitation corsets, lightly boned but have no effect on the figure. Basques are the sexy underwear version of bustiers. Some sellers try to call any gothic fitted top with any laceup pattern a corset, even if it has no boning whatsoever. Bodices are also often mixed up with corsets, they're usually lightly boned garments designed to go over a bodice.
How is the sizing given?
If only a bra size is given, it's a basque, end of debate. I've seen Court Royal corsets sold on a lingerie site with a list of recommended bra sizes for each size, I don't know if that came from Court Royal or the site, and having no experience of Court Royal as a brand I don't even know how authentic they are, but that's the only possible exception to the rule I've seen (I've only seen good reviews of them, but by people who don't know much about corsets). Their main sizing is by dress size, and this is also usually a bad sign. Corsets should be sold by waist size, as they are very precise garments for waist reducion, and I would never buy a corset where the size was indicated by dress size or XS/S/M/L/XL as there is so much inconsistency in these I would have no way of knowing if it fitted before trying it on. But I have occasionally seen ones sold by dress size which showed no other obvious signs of not being a proper corset.
If waist, hips and bust measurements are given, the bust and hips should be around 10" more than the waist (more for tightlacing, can be less depending on your natural shape and how much waist reduction you want). Usually only the waist size is given, and bear in mind this is what the corset reduces your waist to, not natural waist before putting on the corset. If they offer made to measure it's generally a good sign.
What's it boned with?
The easiest way to filter out a lot of the rubbish is to search for "steel boned corset". Also look out for the phrase "lightly boned" in a description and avoid. A tightlacing corset MUST NOT be boned with plastic as it is very dangerous and can snap. All modern corsets I'm aware of are boned with steel, genuine antique ones will probably be boned with something like whalebone or reed. Manufacturers aren't stupid, they don't want to get sued by someone who got stabbed when their "corset" broke, if it has plastic boning then it's not supposed to be laced tight and will probably be too small at the hips and bust for it to be possible. So if it's plastic boned, it's not a corset. Something not boned at all is not a corset and usually hard to mistake for one.
What if the description doesn't say what it's boned with? Generally I'd look at the next few points, if it passes on all of those chances are it's steel boned too. Usually sellers are keen to show off how high quality a real corset is and will make sure STEEL BONED is prominent in the description or title. If it's not and you're still unsure, ask. Be suspcious of any seller who gets offended, someone selling a real corset will probably be delighted that you've done your homework, have shown an interest and given them and opportunity to say how great the item they're selling is.
What's the brand?
Snobx, Vollers, Axfords and Revanche de la Femme are some examples of manufacturers who only do genuine corsets. If the seller gives the brand of the corset and it's not on the list, stick it into Google and see what comes up. If they have a website which blatantly shows they do quality tightlacing corsets, you're probably safe and don't need to check any other features. This assumes the description is correct, it's probably a good idea to check the manufacturer's website and verify that the model is one of theirs. I've never actually seen this happen, but someone could try to sell a complete non-corset knowing nothing about it, someone almost equally non-knowledgable tells them Vollers make all the corsets, so they say it's a Vollers corset. Unlikely, but given the price you could be paying it may be worth checking.
Ann Summers have several "corsets"-don't be foooled by the trusted big name, most of these will definitely not reduce your waist. I tried one on once and no corset at all did more for my figure! They have one or two designs steel boned with a proper busk (see below), I'm still not convinced as a dress size is given and I think they're rather lightly boned and ribbon laced.If it's a brand you can't find any mention of or custom made by the seller it may still be fine, check the construction.
What's the front fastening?
Almost all genuine corsets fasten with a steel busk, this is two steel plates, one with sturdy pegs (usually 4-6) and the other with lobes with holes and the pegs lock into the holes (before the 19th century it was a piece of wood to stiffen the front). It's usually visible on a photo as a series of silver blobs, some have a concealed busk but you can usually just about see the busk. Apologies for the incredibly non-technical description! Some corsets have no front fastening, you'll have to look at the manufacturer (e.g. Snobz and Revanche De La Femme have some) and/or boning for clues. Be warned they are a nightmare to get on and off without help. Vollers have one with a zip, this is a proper corset zip, but be very suspcious of any others with a zip fastening as the vast majority are not up to the job. Some corsetiers don't think a zip, even a corset zip is EVER suitable for a corset so it may even be best to avoid those. A front lacing (as well as one at the back) is the only other acceptable front fastening for a corset I can think of, also going to be a nuisance to put on. Make sure it is proper corset lacing and not ribbon (see below) if it's structural and not just over the fabric for decoration, this also applied to any side lacing. Totally non-structural ribbon decoration or lacing for a couple of inches above the busk is fine.
Many "corsets" have hook and eye front-THESE ARE NOT AND CANNOT BE CORSETS. The front would break pretty soon if you attempted to tightlace one. Corset hooks to extend a busk are OK. I've seen several leather "corsets" with buckles, these will be just as bad as hooks and eyes.
If you buy a corset with a busk, NEVER attempt to take the corset off by opening the busk without loosening the laces. It should be incredibly difficult to do anyway, but if you do manage to start undoing the busk it will put huge strain on the last pegs to be undone and quite likely break them. Getting that fixed will not be as simple or cheap as you think. If your corset has a zip you'll have to be even more careful.
What's the back lacing?
It should be a sturdy bootlace type lacing. If it's laced with ribbon, that's not strong enough. Yes, you could swap the lacing for something else, but the point is if it's designed for tightlacing, it will have proper corset lacing with it. If it's not laced at the back then it's probably not a corset, unless the seller has managed to demonstrate it back to front. This is not impossible, I've seen them modelled upside-down! Front laced only corsets are very rare, it would probably be done more often if it was a sensible way of doing it. A fully closed corset should have a large amount of loose lacing which usually gets tied up in an enormous bow looking like a mass of spaghetti at the back. If it has a tiny neat bow at the top then there's no way it can be loosened far enough to get on and off and lace tight enough to reduce a waist.To put on a corset, if it hasa front busk then you open that, undo the laces until the corset matches your natural waist size, do up the busk and then tighten the laces, usually 2 loops at the waist. For a corset that pulls your waist in by 4", that's going to need a LOT of slack to be able to open far enough to get on and off, a little piece of ribbon is not going to do the job! It's also going to be taking large forces at the waist, so you don't want anything likely to snap.
What fabric is it made of?
This probably won't be much help as usually only the outer finish is given in the descripion, but a true corset has to be made from at least one layer of strong and non-stretchy fabric, usually a special corsetry coutil. If it's a blatantly some stretch mesh, or the decription says it stretches, steer clear. A good sign is if the inside is black or white when the outside isn't (if they show the inside), it's probably been lined for extra strength. If they name the fabrics used and none is described as coutil that's probably not good. Other fabrics some people use include heavy drill, duck and linen. As long as it uses one of those the outer finish can be anything. Personally I've had issues with velvet having a habit of not standing up to the high tensions of a corset even with a decent coutil layer underneath, although the corset in question was rather cheap and probably given more abuse than it was designed for.
So, is it a corset?
If the item you're planning to bid on fails on a single one of the above points, then it is NOT a corset. If it passes on all the ones you can see and you're not sure on others, a reliable brand is always a pretty sure thing. I often put in the search term corset (snobz,axfords,vollers) which comes up with no rubbish at all (but sadly tends not to have bargains in my size either). Steel boned, good busk, waist size in inches and back laced with decent lacing is usually all you need to know.
Finally, once you've established that what you want to bid on IS a corset, I'd recommend avoiding ones which have been worn a lot by a previous owner, new or worn once is preferable. A new corset does not take kindly to being tightly laced, you'll have to break it in first by wearing it for a few hours not laced more than 2". A burst seam is generally not quite as bad as a broken busk but still not what you want! A good corset becomes shaped to your body and you become shaped to it over time, it's a very special and personal garment which is a joy to own and wear and well worth reading my ramble for if you want to experience that rather than get ripped off with a cheap imitation!