Tuesday, October 28, 2008

Analysis of the "Swayback," the making of V8532

In spite of my blog silence the past month, it does not mean my sewing machine has been in hibernation. In fact, it's been quite busy, sewing up a few projects. None have been completed though because of the issue of my dreaded swayback. The latest project to fall victim to the swayback, is Vogue 8532, a lovely alternative to the classic sheath. Empire waist, fitted design, and my favorite and most flattering neck line. Observe...

I've sewn up a muslin because the sheath would present serious fitting challenges that would have to be worked out before cutting into fashion fabric. In that effort, I've consulted at least a dozen sewing resources trying to establish the best and most effective (read: easiest) way to alter the pattern so that 1) I'll have this awesome dress to strut my stuff in and 2) basic alteration I can use for most similar patterns.

The swayback is my greatest fitting issue and has been the source of pretty much every single UFO in my closet. Most patterns (and RTW clothing) are made from slopers that conform to more universal measurements, meaning they fit to the least curvy denominator. So, it then falls to the sewer - or tailor if you are not sewing inclined - to alter patterns to fit your various curves and hollows. After consulting various sewing resources, the most common fix mentioned is to remove the excess fabric at the back waist by taking a "horizontal tuck" until smooth. Also, this is typically accompanied by letting out the side seams or center back seam to achieve the perfect fit.

In V8532, I tried the "tuck" method. First, I sewed up the unaltered pattern and tried to pin out the excess fabric from the back and sides. Emphasis is on "tried" because it's exceedingly difficult to pin fabric while you are wearing it as every move, twist, bend, contortion attempted pulls and creates yet another wrinkle. Anyway, I was able to guestimate well enough to determine I needed to remove a full 1" from the back waist. I did this by cutting the pattern along the waist line from center back seam to side seam. At the CB, I removed an inch and then drew a line to taper this to the side gradually to nothing. I also had to increase the dart. Here is the result; the original pattern is underneath and my alteration is on top:

Here it is sewn up, from the front and the side. I wasn't able to successfully photograph myself from behind but you can get a good idea of the issues that remain, even with my fairly significant alteration. The wrinkles on the front are because of the way I cut the front piece after the first sewing. Let's just say I can cut a straight line but curves are another matter entirely...Anyway, once I smooth out the actual patter, I expect the fronto lay smooth(er). I have a much bigger issue with this image of the side. It's just as bad on the right as the left. That wrinkle starts from the left waist and extends to the bottom of the dart. I'm not really sure how to fix it, either. Any suggestions???

What is a sway back you ask? Good question, because it is the subject of some discussion lately and people really wonder exactly what is the swayback. From an anatomical perspective, it is a condition called "Lordosis," where the spine curves inward between the ribcage and the pelvis causing stress and discomfort. It can be from general bad posture or be physiologically based. Here is a good image of what it looks like in silouhette:

The sway back affects the way clothing fits and is typically diagnosed by the resulting "wrinkles" or "pooching" at the back waist, above the hips. The wrinkles can also be caused by proportionately large hips (waist:hip ratio), otherwise known as having, well, a big butt.

In my next post, I'll be highlighting how different authors deal with the swayback. Stay tuned and please, feel free to chime in with your particular fix! I need all the help I can get!


Chicago Sarah said...

I'm afraid I have no tips but am anxious to follow this posting! If you come up to Chicago I'll help you pin- you can even use my machine so you don't have to check yours. ;)

LMH said...

It's really hard to say without seeing you in the dress as originally drafted, but I'm guessing you got those drag lines because you took fabric away, when what you need is to release more fabric to go over your curves. Did you try shortening or decreasing the back darts from the waist down? If those (and the side seams) are too close to your body where it widens out the most--and in a sheath dress they do tend to be close--they can make fabric pool above them, i.e. bunch up at the waist, even if as a whole you have enough circumference in the dress to go around you at the widest part.

Another important clue to what is going on would be to see what the side seams do in the garment as originally drafted--do they swing forward or back or hang straight. The answer to this will also help know what to do to solve the fabric bunching problem at the back waist.

I guess I would 1) cut a new muslin in the original draft; 2) let out the side seams from the waist through the hips; and 3) let out and possibly shorten the back darts. The right combination of 2 & 3 might release enough fabric at the right point to let the dress fall smoothly in back.

Also check the hang of the side seams to see whether it's being dragged forward or back. If they swing forward you may need to adjust the front instead. You might also need to adjust the front darts (in length as well as how much they take in) to allow more fabric released where you need it over the stomach and hips. It may be that you need to adjust both front and back darts, as well as the side seams.

Sheath dresses are hard to get close-fitting without any fabric bunching up or wrinkling or making drag lines. If you want them really close fitting like they used to wear them in 50's movies, then you need 1) industrial undergarments! and 2) to do some special cutting/drafting things to minimize the fabric bunching/wrinkling issues. 3) some people who are notorious for their love of pencil slim sheath dresses (Victoria Beckham!) are also notorious for starving themselves into pencil thinness. It might be better to go for a body skimming, more loosely fitting sheath dress?

I hope all this makes sense; it's hard to explain & of course it may be all wrong and not helpful at all. But I thought I'd try. All this is based on Natalie Bray's Dress Fitting book. She also says that slight wrinkling in the back because of a swayback is okay and can be ignored if it's slight and only seen when you're in motion. Good luck with this! It's a cute dress.

debbie said...

Coming out of lurking to offer some help.

I have a pretty severe swayback also and alter ALL patterns because of it! Some as much as 2".

The way you did the alteration is the way I've always done mine w/much success.

Without a back pic I'm guessing it's prob 1 0f 2 things- zipper length and/or a bigger swayback tuck. With a longer zip and swayback the zipper is trying to lay flat over a very curved back and they don't like too! I usually try and use the shortest zip I can, just past my waist. That eliminates some of the curve factor.

After all that my suggestion would be try a shorter zip first and then see if it lays better. If not, you need to increase your alteration. I also think some of your front probs may smooth out when the back lays better.

Hope that wasn't too long winded!

patsijean said...

I notice that the dress is pulling at the front thigh area as well as at the seat. I would guess that you might want to go up a size from the waist down. You don't want that pulling at the thighs which results in cupping under your stomach. I cannot tell from your photos if you made your sway-back alteration in the center back tapering to the original side seam. That also may make a difference as it looks as if the back side seam may be shorter than the front side seam.

Birgitte said...

I'm flat as a plank myself but DD who's now 15 is swayback with a beautiful large tush :)) I've been draping her since she was 7. You need more fabric over the tush and in this pattern you have the following seams to work with; sides, darts, and center back. I often use the CB even with a zipper, contouring it to fit. The best fabric to work with is muslin because you can clearly see the grain and cross grain and it is stable. It's also easy to mark- I often draw black arrow lines to mark the grain lines so it's easy to see in the mirror.
Like Imh said, you can let out the side seams/darts to see where the skirt falls. You can also slash- I do a lot of slashing :)) But I think you'll save time by doing the whole procedure on muslin fabric.

Danielle said...

I was searching online for awhile and finally found something that helped me. I am making a dress for my cousin in-law and came across the same problem with her pattern.
thanks so much for sharing us.