Corset Talk: Are Spiral Bones Better Than Flat Steels?
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Corset Talk: Are Spiral Bones Better Than Flat Steels?

© Joel Aron : Allie Diane for Dark Garden

© Joel Aron : Allie Diane for Dark Garden

There's a lot of confusion and misinformation about corset bones that get circulated. I mean, first of all, why are they even called bones? The term originates from whalebone, which wasn't bone, but baleen, the filter-feeding system used by some whales. Then there's the raging debate as to whether flat steels are superior to spirals, or vice versa. Flat steel boning is made of strips of spring steel sheets, carefully blunted on its sharp edges and coated with a rust protectant. Spiral steels take the form of a flattened coil, carefully capped, and are noted for their greater mobility.

Well, not to cut myself off here, but there is no objective superiority between flat (spring) and spiral steel corset bones. It all entirely depends on the intended placement of the bone and intended use of the corset. Which is to say, there are advantages to both types --- depending on the circumstancesWhen ordering or purchasing a corset, knowing your preferences and needs regarding boning can be incredibly valuable. (Corsetieres interested in learning more on the subject will probably enjoy Jenni "Sparklewren" Hampshire's post on Foundations Revealed, "Comparing Steel/Spiral Boning.")

© Mariah Carle : Victoria Dagger in Sparklewren

© Mariah Carle : Victoria Dagger in Sparklewren

First, it's important to note that boning comes in various qualities, like every other corsetry compenent. And I don't just mean quality as a good/bad spectrum, but rather attributes. Before my last trip to England for the Oxford Conference of Corsetry, for example, I had never encountered flat steels so stiff! Except, perhaps, in my English-made Sparklewren cincher sample some years prior. Whether that's a feature or deterrent depends entirely on the intended use. Also remember that boning only supports and enhances the shape enabled by the fit patterned into the corset.

© Sam Guss : Victoria Dagger for Pop Antique - flat bones are always required to support the center back lacing grommets.

© Sam Guss : Victoria Dagger for Pop Antique - Flat bones are always required to support the center back lacing grommets.

Lacing bones, which have pre-cut holes for grommets, are generally noted to also be quite stiff. On some figures, this may equate to greater stability; on others (such as curved sway-backs), this may create uncomfortable pressure. Even without lacing bones, though, it seems to be universally agreed that the grommets at center back must be supported by flat steel bones. (If there are any exceptions to be had, I would love to hear about them in the comments below!)

Dark Garden Risqué Cincher | Model: Kali | Photo © Marianne Faulkner

Dark Garden Risqué Cincher | Model: Kali | Photo © Marianne Faulkner

Conversely, spiral bones are always needed on any seam that has a lateral curve as well as a vertical contour. Any bone channel that is curved on a style line (rather than tracing a straight line down a curved form) will certainly require a spiral steel bone. Depending on the style of corset, spiral bones may be required to fit the style line.

© Joel Aron: Nicole Simone for Dark Garden

© Joel Aron: Nicole Simone for Dark Garden

On plus size figures, I've heard it both ways. "Flat steels are too poky, and dig in!" versus "Spiral steels aren't supportive enough!" Ultimately, this means that it may just come down to personal preference, which is no help when shopping for your first corset. (Sorry.) On bony figures, though, I would almost always recommend spiral steels. If you have a highly compressible rib cage, it may not be an issue, but with protruding ribs and hip bones, flats are liable to cause bruising. I always describe spirals as being able to achieve a "more complex" contour --- they easily trace the swell of a bust, then the curve of the ribcage, a subtle indent of the waist reduction, and then gracefully round the hip bone. This is why some corsetmakers use spirals for seams that cover the bust, even if they use flats in all the other channels. A flat steel bone, unless pre-contoured or broken in to a certain curve, will skim the outermost convex points of those curves and chafe.

Speaking of pre-contouring flat steels, do note that curved steels are not the sign of an inferior garment. Cheap plastic bones will crumple like an accordion under stress. Flat steels will mirror the curves of the corset pattern and the body that wears it, and can intentionally be curved to do so. I like to contour the center front of my corsets to minimize pressure on the solar plexus and, well, guts, as well as the side-seams on my ribbon corsets to encourage the straight ribbon edges to curve rather than simply flare.

© Bill Clearlake : Victoria Dagger for Pop Antique

© Bill Clearlake : Victoria Dagger for Pop Antique

If you're really curvy, you may be better off with spiral steels. Why? Well, as Ani DiFranco says, "What doesn't bend, breaks." Which isn't to say flats don't bend (since I just said they did), but they don't bend as far or as comfortably as spirals. At Dark Garden, I just took a friend's corset in to be repaired: two of the flat steels had snapped right on the waist line side seam. I showed our production manager and she said, "It looks to me like she's really curvy. We should replace these with spirals, because those don't break." She was right, the friend is very curvy, even without her corset on, which she wears daily for an impressively rigorous schedule of work-related travel and personal activities, and though the spiral steel corset I'd made her two years ago has worn out in some places, the bones themselves remained true. Again, your mileage may vary according to personal taste and the source of the boning in question, but it is well worth considering.

Dark Garden at Edwardian Ball - dancers and circus performers often require spiral boning for increased mobility

Dark Garden at Edwardian Ball - Dancers and circus performers often require spiral boning for increased mobility

Another instance in which spiral steels may be preferable is when the corset is intended for performing. Dancers and circus performers often need the extra mobility provided by spiral boning.

Dark Garden "Pearl" corset | Model: Autumn Adamme | Photo © Joel Aron

Dark Garden "Pearl" corset | Model: Autumn Adamme | Photo © Joel Aron

Waist trainers and tightlacers are another bunch that can go either way. It may be easier to cinch to smaller reductions with spirals (results may vary!), but they may also lack the feeling of constriction and confinement that some tightlacers not only enjoy, but crave.

What's your preferred boning type and why? Share your opinions and experiences in the comments below!

Marianne Faulkner

Marianne Faulkner is the designer of Pop Antique, a clothing and corsetry line specializing in sustainable materials and comfortable curves. She is based in San Francisco where she earned her MFA in fashion design at the Academy of Art University, and has been a columnist at The Lingerie Addict since 2011.

9 Comments on this post

  1. Derik Shopinski says:

    I’m looking for any help understanding why the spiral steel bones in a ready-made longline corset bra have bent and distorted out of shape. I have not knows this to happen. The bra is not too small, which you would assume cause the bendage in the bones. Any ideas? Comments?

  2. Lauren says:

    Hi, I’ve been tight lacing on and off for some years, currently down to 23″ from 31″, I’m naturally very curvy (42-31-43) and I have a sway back and I’m very short waisted (so many things to accommodate). This said I have found that gently bending the flat steels at the back of my corset is enough to accommodate the curve of my back. I prefer a very stiff wide steel busk with flat steels in the front to make it easy to get in and out of my corset and prevent it from bending inwards too much at my waist and spiral steels at the sides to move over my extreme curves, they offer the best combination of support and freedom of movement.

  3. While I agree with what you say, I think the thickness and quality of the bones matters in the discussion. In general, spirals are much more accommodating and forgiving to a variety of figures than flats, which can cause pain and even injury. I’m among those who have snapped flat steels (both in front and at the rear) due to my curvy figure, so I prefer spirals wherever I can. I’ve also found that I need the most flexible flats possible at the back to avoid aching in my ribs/back after several hours of wear.

    I advise people to look for spirals if they don’t know what they are doing specifically because they are more adaptable and also because the low-end corset brands are using very stiff, low quality flat steels that don’t give much shape and cause discomfort. Unfortunately a lot of corset wearers out there don’t know how comfortable a corset can be because they are used to low quality. So it’s not that flats can’t be used effectively and appropriately, but that it takes more knowledge and skill to do so, so the chances of getting a comfortable corset are greater with spirals.

  4. KathTea says:

    If there’s one thing I learned, is that there are no fixed rules in corsetmaking :)

    For instance, while for most corsetieres, waist tapes are a must in their construction, BizarreDesign and Contour Corsets both engineer their corsets to be sturdy enough to not need any. I have a secondhand BizarreDesign and I am impressed at how the shape of the corset holds itself even when laid flat.

    As for flats, I’m definitely not the biggest girl around yet I am hardly skinny, but applying pre-bent flats on the sides of my corset allows for quite a smooth wasp/conical silhouette. This is also evident with a client who had bought the exact corset from myself. My natural waist is around 27″-28″ while my client is more around 25″ and is much more slender.

    These days, while shopping for materials (on Sew Curvy & Vena Cava) both flats & spirals now come in various widths & thickness. Some spirals are stiffer than some flats and vice versa.

    This also applies to various factory-made corsets from Pakistan, India, Thailand, China, etc. I’ve read some personal accounts on Tumblr sharing the results of dissecting some of these corsets. A popular Indian manufacturer uses very stiff steels in their works, so much so that even a 2″ reduction hurts! Some corsets in China may seem like plastic boned pieces but upon dissection, they may actually have spiral steels! I suspect the steels used in these are the narrower, thinner kind used in orthopedic knee braces.

    Additionally, there are also designers like Arwen Garmentry & Gallery Serpentine out there that sometimes use stiffer plastic boning for well-shaped corsets too!

    This is what fascinates me when it comes to corsetmaking. The rules are there but they can, with care, be broken to create interesting results :)

  5. sarah says:

    While making corsets I like to use both… flat steel on my support lines and spiral on my d design lines. Don’t know why high end corsetry doesn’t follow suit.

  6. AlexaFaie says:

    I’m about to try some flat 5mm wide steels for my Edwardian reproduction (Atelier Sylphe Pattern Ref W) for which they were recommended to me, but so far I’ve found that I prefer spiral steels.
    I’m in the curvy back group and have found that the comfiest corsets I own are a custom one I ordered where the corsetiere only used one steel to support the eyelets (none on the outer edge) and the corset I made on the course which uses plastic boning because the lady said that it was the best representation for whalebone and she didn’t have any flat steel I could use any way. The first with only the one bone has held up remarkably well considering that the eyelets are not fully supported. There is some wrinkling at the waist, but the eyelets haven’t come out, not even close to it.
    I’m looking forward to experimenting with different techniques for boning by the eyelets to see what works best for me.

  7. Karen says:

    Wonderful article, and it makes a lot of sense! The last two good quality corsets I had from Meschantes Corsetry had a combo of both. I’m a plus sized figure, pretty straight up and down, with a round belly, so I liked having the flat boning in front to really pull my tummy in and give me a smaller waist size – but the spiral boning on the sides helped to shape my waist and give me that really curvaceous look I wanted. I guess it really depends on what the buyer is looking for!

  8. SophieHMS says:

    Great in depth article!
    I personally prefer spirals. One of my made to measure corsets combines both and I can experience a bit of discomfort/chafing around the front rib area with the flat steels. I am a size US 8 with some cushioning. ;)

  9. Natalie says:

    Really interesting article! Thank you for your insight into the different pro’s and con’s!

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