the perils of sewing PVC: or, sexy Harley Quinn costume in vinyl

(I know that several of my readers drop by here looking for advice on how to sew PVC (Patent Vinyl Cloth), so scroll below the pics for my tips and tricks.)

Back in 2002, when I made that first Harley Quinn costume, I proclaimed loud and wide that it was the hardest thing I'd ever done.

For years, it held that dubious honor.

Now I have completed my first Harley Quinn costume out of PVC/Patent Vinyl Cloth/4-way stretch vinyl, and I can confidently say that IT is the hardest thing I've ever done. I think I actually made up some new curse words while sewing it.

But here it is (click through to Picasa for more images, including the updated hood):





Don't mind the wrinkles around the body--my mannequin is a size 2 and that costume was made for a 5'9" Amazon. I'm actually quite pleased with the way it came out, enough so that I've almost forgotten what a headache it was.

Marking and cutting

There are 57 pattern pieces to making one Harley Quinn costume, not including the poms and zippers. I can cut out a spandex suit in an evening, in part because the fabric needs little tailoring, and I can mark pattern adjustments once and then cut both layers, at the same time.

With the PVC, that's not necessarily the case. In the first place, you can't pin your pattern to the fabric; any pins you put through the shiny coating will leave holes. Even if you don't mind the holes, the vinyl is so tough and dense that it kills your fingers to push a pin through it, and forget about pinning two layers together. They stick to each other, catch and stretch and create wrinkles.

The alternative is to trace around all the pieces and cut along the lines. This, too, is easier said than done. Marking on the shiny side of PVC is vitually impossible. Marking on the back side is not too bad, unless of course you are trying to mark on black. The best solution I found for this problem is plain ol' tailor's crayons, which are squat, squarish tabs of a chalky-waxy substance. They are not terribly precise, but they mark easily, boldly, and stay put. Be warned, however: the crayons leave a visible, withered-looking line on the shiny side of the fabric, so only mark areas that will be inside the seam allowance.

Cutting PVC with shears gets very fatiguing, very quickly. Also, when you can't pin your two layers of fabric together, it pretty much eliminates the possibility of cutting out two layers at the same time. The best tools for cutting PVC are a rotary cutter and the largest cutting mat you can afford. Another useful tool is one of those plastic French curves used to draft patterns. You can lay it on the piece you're cutting out, turning it along the pattern lines as you cut. This gives the rotary blade something steady to run against, and you never have to lift the blade from the fabric. For best results, cut on the backside of the fabric; otherwise the shiny stuff will stick to your blade.

With a little practice, I was again able to cut out two layers at the same time (right sides laid together) and the rotary cutter is actually faster and easier on your hands than a pair of shears. The only downside is the blades are rather expensive, and have to be replaced frequently.

Fitting

Spandex stretches a LOT. PVC stretches some, but not enough to compensate for poor fitting. Wearing a too-tight PVC garment can actually be painful, especially at the smaller joints--the elbows and hands. Also, if the fit is too tight, you get unsightly fold-lines radiating out from points of stress. The good news is, PVC is pretty tough. I have not yet managed to tear out a seam, even while doing kung-fu kicks in my Catwoman suit. Even so, it's a good general practice to sew with a thread that's weaker than your fabric. Don't use heavy-duty thread or nylon filament. If the thread breaks in a seam, it can be replaced. If the thread cuts through your fabric, you're screwed.

Generally I plan for zero-ease fitting for a PVC garment, depending of course on the design and the client's desired look. The Harley pattern I use does not have allowance for bust darts, so I add vertical darts--I draw the upper front of the suit with additional width to match the bust measurement, and then take in darts at the shoulder seam and underbust until those measurements are reduced to the correct width. For very busty girls this sometimes requires a lot of taking-in!

Likewise, if there is a large difference between hip and waist, I cut to the hip measurement and take in the waist excess with darts, where princess-seams would ordinarily go. Curved darts, spaced around the body, will lie more smoothly than a flat piece of fabric strained tight around the waist.

Oh, and make sure all your pieces are long enough. Cut for the full length of the client's arms, legs, and torso.

Sewing
A serger is ideal for constructing all types of stretch fabrics. The edges of PVC don't have to be finished, but a serger seam is best because:

a) it stretches,
b) the double-stitching line is stronger than a single and prevents skin from showing through a strained seam, and
c) covering the raw edges makes the garment glide on and wear better, since the shiny parts cannot then stick to your skin.

However, if you don't have access to a serger, you will need to use your machine's stretch stitch, and experiment with different thread tensions and stitch widths. Do a test seam and then stretch along the seam until it breaks. Revise accordingly. Often you will have to compromise between appearance and stretch; however stretch is really only crucial in the long seams, the legs and arms, and if you have fitted correctly, those seams will not need to stretch while they are being worn. The only time I have popped a non-serged seam in a stretch garment was while pulling on the legs too fast.


Actual construction is easier than you may think. In fact for the majority of seams (sewn right sides together), PVC is no more trouble than cotton, because it doesn't crawl against itself or slink around, and you can easily coax the curves against each other. Again, you can't pin-baste pieces together without leaving holes, but the PVC has enough body you don't usually need to baste. I do pin-baste the tight curves, i.e.: around the armholes, horns set in the hood, and thumb inset, you just can't line up those curved seams under your needle without pin-basting.

Many people find that their machines want to skip stitches when sewing PVC. If you are having this problem, there are several things you can try:

1. Use a new, 'Sharp'-type needle --NOT ballpoint, NOT Universal, NOT leather. I have also had good results, recently, from a new variety of needle labeled "Stretch." Klasse and Schmetz both make these (there may be other brands for your machine), but so far I've only been able to find them in size 11, which is a little bigger than I like.
   
2. Increase the stitch length, i.e. if your machine has a dial from 1-10, use a 6 or greater.
   
3. Use both hands to keep a slight front-to-back tension on the fabric as it goes under the presser foot. Don't stretch it enough to distort the fabric, just keep it taut so it feeds more smoothly.
   
4. Reduce the thread tension on the needle thread *slightly*
   
5. Change your needle position from left to right. Most machines have a sweet spot where the bobbin thread catches better. This may not be possible if you're using a special foot where the needle has to be in a particular position.
   
6. Clean out the lint under the needle plate, and remove the bobbin case & carrier and oil the socket where the carrier/thread hook rides. Seriously. You'll be amazed what a difference this makes, especially when your machine is hot.

The other special headache about sewing PVC is that it sticks to the metal parts of your sewing machine--particularly the presser foot and the needle plate. This severely crimps the possibility of topstitched finishes, which I happen to like and which are necessary, in many cases, to get crisp, tailored lines in your PVC garment.

There are a few ways to ease the sticking. The best one is to get a teflon-coated (nonstick) presser foot. I got Bernina zipper foot number #57 for my 930, since I mostly use a zipper foot for narrow topstitching; it was about $60 and worth every penny. One caution: be careful not to let the rear feed dog contact the back of your presser foot or it will scrape off the teflon!

If this special foot is not an option for you, you can cover your presser foot with masking tape. This helps a great deal. You can also keep a small dish of cornstarch beside your machine, dip your fingertips into it periodically and swipe the starch along the seam you are about to sew (top and bottom). Cornstarch used in conjunction with a teflon or tape-wrapped foot makes all kinds of things better.

Other sewers like the tissue-paper method, but I don't, so I won't talk about it here.





Happy sewing, and please feel free to contact me with questions!