Problems with Bias

I just now received a comment on an old post regarding bias cut. I thought it was worth re-visiting the subject and posting my response here.

Anonymous said:
A wonderfully informative article, Dawn!! I had a bias cut dress sewn recently, but while the drape in front was very good, the back has one large fold of fabric, almost like a pleat, right across from seam to seam just above the butt. Why is this happening?

First, Thanks!

There could be a couple of things going on.

It could be that the dress is too snug across your butt and hips to slide down past them. However, were that the case, you would probably have horizontal ripples, or waves, across the fullest part of your hip or butt (see below.)

Given the absence of obvious stretching across your hips, it sounds like there may either be too much width-wise fullness over the small of your back, or the waist is too long for you. In the latter case, the long waist does not show up in your front b/c you're relatively flat there and it just slides down. There is nothing for it to get "hung up on."

If there is too much width across the small of your back you could take in the back side seams only. But you have to be careful.....pulling width wise on the bias will cause it to draw up lengthwise in the back. I have tried to place princess darts in the lower back of bias garments with moderate success. You have to be very careful to get them placed right and avoid wavering while you sew.

If the waist is too long you could add a seam, perhaps an empire seam. Again, great care will have to be taken to sew it neatly in the bias and after the seam is added you may need a closure of some kind. Obviously the dress is going to get shorter, at least in the front, unless you add some kind of trim to the bottom.

In cases where a bias dress is too tight over the butt/hips (i.e. there is rippling across the fullest parts), here is how it could happen, even when using a perfectly fitting pattern (and I learned this the hard way):

Bias will stretch so much that the width of the garment pieces becomes significantly narrower. To make matters worse, the waist shaping at the sides seams drops lower as the pieces stretch. So, you can end up with waist shaping quite a bit below the waist and a much too small hip area.

So you have to cut *huge*, maybe 2" seam allowances on the sides. that way, after hanging and stretching, you can let out the side seams at the hips.

Alternatively, you could cut huge bias rectangles and try to stretch the fabric before cutting the garment pieces out. But I'd still leave huge seam allowances.

If anyone would like a custom bias dress my going rate is half a mill per hour.

Undercollars Part 2 - Grain

Collars fold and curl and turn, so it makes sense that they should be cut on the most supple, malleable "grain," bias. This may not be quite as crucial as the shape and size of under collars, but the two techniques together do make for a beautifully curling, smooth, faultless collar.

Just to review, here is a comparison of the two collar pieces of Vogue 7467, a suit jacket pattern.As noted yesterday, the under collar piece (here, the lower piece) is smaller in size at the edges (not the neckline.) Note now it also has a center back seam, and a bias-oriented grain arrow. Let's re-draw the grain arrow. When you're drafting the under collar piece yourself it's easier to draw that grain arrow as a 45° line from the CB seamline. Remember, the grain of the upper collar runs along the CB. We want the under collar to be exactly bias to the upper, or 45° off. I've drawn in a new grain line with green marker. My grain line is perpendicular to the pattern's given grain line...that's OK, because we'll be cutting two under collar pieces and they'll be perpendicular to each other anyway.

Early on in my sewing life I must've read that bias under collars were a good thing....but hadn't read yet about creating smaller under collar patterns. So, in making the little fleece and corduroy jacket I'm about to show you, I diligently cut a bias under collar. But I cut it with the upper collar pattern piece, and on a fold. In other words, I cut it on a bias fold (thinking myself Oh So Clever), like this:Well, here are the less than ideal results. Firstly, can you see all the bunching of the corduroy under collar? There is too much fabric b/c I used the upper collar pattern to cut it. Second, and this is what's most important today...look at the grain of the corduroy and keeping in mind that the wales of corduroy represent the lengthwise grain....can you see that the lengthwise grain runs into one collar tip, and across the other collar tip? In other words, both collar tips are cut on bias, but one tip is "dominated" by the lengthwise grain, and the other is "dominated" by the crosswise grain. And b/c lengthwise and crosswise grains are so different, the collar tips will behave quite differently. (In this case one tip will curl up in a more pronounced way than the other since the under collar is too big in the first place.)This is why anytime you cut something with a bias orientation the bias must be balanced. And *that* is why we've added the CB seam.

In order to mirror the under collar pieces you must cut them on a single layer of fabric, flipping the pattern perpendicular for the second piece. Like this:
first piece:second piece:or, alternatively if you create two under collar pattern pieces the layout it will look like this:When sewn, this mirroring effect will create a nifty chevron effect on plaids or stripes at the CB under collar, like this:There are umpteen ways to construct collars and I'm not prepared to go into those now. But one thing is constant for me....understitching the under collar. It may be done with invisible hand-stitches, prick stitches, machine straight stitching, or even, in the case of heavy spongy wools, zigzagging, but it is the icing of the cake of collars!

p.s. I finally noticed that "upper collar" and "under collar" are not compound words! I hope you'll forgive me if I don't go back over the past 6 months of posts and correct them all...

The Fishline Hem

The fishline hem is without a doubt my favorite sewing "special effect." I insisted on this finish for my bridal veil before I knew what it was called, or even knew the first thing about sewing or fabrics.

A fishline hem is sort of "bouffant." It has graceful, bouncy, scalloped curves supported by monofilament nylon (fishing line) sewn into the hem. The easiest way to make a fishline hem is with a serger though I'm sure you could use a conventional machine with a zigzag stitch.

Any threads can be used in the serger, including decorative threads such as metallics. If you use a decorative thread in the upper looper, you may want to de-emphasize the needle and lower looper threads by making them the same color as the fabric, or using invisible threads. (You can also do a fishline hem with a 2-thread serger rolled hem for the most delicate effect.)

The fabric should be lightweight enough to work well with a tiny serger rolled hem. The lighter and stretchier the fabric, the more it will curl. Bias cut chiffon or organza work great. Tulle makes beautiful curls. Knits also work nicely.

I have used 20 or 25 pound fishing line. The former is a bit more delicate, the latter will give more pronounced curves.

Here are the steps:

• Cut your fabric on bias or, for a knit or tulle, on the cross grain.
• Set up your serger for 3-thread rolled hem and test it out to make sure it's making a nice, neat edge.
• Place the spool of fishline in your lap, unraveling a couple yards.
  
• If you have a serger foot intended to guide cording, place the fishling line through the hole. Otherswise, you can easily guide it over the "toe" of the foot, then under the needle/loopers as you serge.
  
• Pull at least 10" of fishline to the back of the foot.
• Start serging, making sure the fishline is getting caught in the "roll" of thread.

• Serge about 6" over just the fishline before introducing the fabric. You now have quite a bit of fishline and serged fishline behind the foot.
• Introduce the fabric. You may have to adjust setting to produce the nicest finish. (i.e., if you are getting wiry fabric ends poking through the roll you could increase cutting width to roll more fabric into the hem and/or decrease stitch length to provide more coverage.)
• Serge slowly, making sure to gently guide the fishline. It is easiest if you hold the fabric "tautly" as it goes through the foot. For more immediate curling, stretch the fabric as it feeds. Note in the photo below, I am holding the fabric taut as I also control the feed of the fishline.
• At the end of the fabric, continue serging for about 10" over just fishing line.
  

• Your work may already curling. (My bias muslin sample is not very curly yet, above. It's a fairly heavy fabric for the 20 lb. fishing line. But to make the curls even bouncier:

• Starting in the middle of the hem edge, grasp the hem b/w left thumb and forefinger and use your right hand to slide the stitching over the cord outward towards the ends of the seam.
• Keep working the rolled hem outward. You will see that as the accumulated bunchiness of the threads gets to the edge and then passes off the edge, the excess fishing line that you left there gets "taken up" into the hem. (****Therefore, the longer your fishline ruffle will be, the more of the fishing line you will need extra at each end of the seam before you start!)
  
• The more you stretch and spread out the edge, the curlier it gets! Here is my muslin sample again:

Now you can experiment with decorative threads. Metallic is my favorite. Here is a fishline hem on tulle with variegated metallic in the upper looper:
or gold metallic on peach tulle:
I have also used woolly nylon with metallic sparkles in it. That is available in many colors. Rayon threads are also nice over fishline hems. I like the stitching to be fairly open (longer stitch length)....then the curl seems to "float" around the body of the garment, especially if you've used invisible thread in the needle and lower looper. All that shows is the decorative thread in the shape of the curl, floating around the edge of the fabric.

Fishing line is also available in some crazy fluorescent colors. I bet one could create some interesting effects with those!

Don't forget, you can also use fishline in a 2-thread serger rolled hem for the most delicate look of all.

Bias Strip Facing

There are several ways that bias strips can be used to finish opening edges such as necklines, armholes, waists, and hems. This is one of the easiest, and since I was in the process of assembly-lining 3 jumper dresses for a client utilizing this treatment, I thought I'd take photos and share the technique with you.These are cotton, yoked, gathered jumpers. The armholes are to be bias strip finished. The "skirt" is in 4 pieces, one front, one back (each gathered to the respective yokes), and an underarm piece on each side. I already gathered the front and back center pieces to the yokes and lined the yokes. Then I stitched the underarm pieces to the front only on each side. I've left the back underarm seam un-stitched. If you have only one underarm, or side, seam, you will leave that open. This allows you to attach the bias binding while the garment is "flat."

In order to obtain true bias strips the best method is to tear across the cross grain (fabric will always tear in a straight grain line), then match up the cross grain tear with the lengthwise grain selvage, forming a point in the corner where they meet. Imagine there is a fold across the top of this triangle. I'd cut my strips before I thought to take the picture. The true bias runs along that fold, 45 ° from both the selvage and the torn cross grain.



I like a 3/8" finished binding, and they will be folded in half twice. So I cut my bias strips
(3/8" X 4) + 1/8" = 1 5/8" wide.

Once you've cut your strips you have to steam press them into shape. Gently fold them in half lengthwise, slightly stretching the folded edge to create a curved shape. That curve will allow it to line up nicely with the curve of the armhole. If you are going to be finishing a waist or hem edge, you do not need to press a curve into the bias, just press it gently lengthwise.









I ended up with a pretty pile of curvy bias strips.

Now it's time to attach the strips/facings to the armhole edges. Having placed the strip down on the right side of the armhole, folded edge in, I can sew right down the middle.Seam allowances must be trimmed and graded. This is easily accomplished with one of my favorite notions, the duck-bill applique scissors. The trick is in how you hold the scissors, as flat as possible to the surface of the garment.

See, at right, how the edges have become staggered. Always grade so that the longest edge will be up against the garment front. This will prevent the "steps" of the shorter layers from showing through when you press.

This is the point at which I close up that underarm/side seam. Be careful of just where you line up the bias facing edges so that when you open the seam, the bias tape will be as even as possible. Sew like this, left -

- with seam starting right at juncture of the two bias tape folds,
to get this, right, when you open it up -

Serge finish the seams, then you're ready to turn and press the facing to the inside:
And stitch it down, close to the folded edge:
And the results are like this:

Circle Skirt Variations

Once you understand how to draft a circle skirt, why not experiment with some variations?

You can draft a handkerchief hem like this. You simply draft a circle skirt and square off the outer circle.




A full circle (or square) skirt has all grains in it. Lengthwise, Crosswise, and Bias. That can make it tricky to hem.

Perhaps you'd like a straight grain skirt, and you're not a Spanish dancer so you'd prefer the fullness of just a half circle (and a half circle skirt is still very full.) How would you do that?

Gores!

Draft a half circle skirt by doubling your waist measurement. Divide half the resulting half circle into 6 equal sections. I would add seam allowances to the gore piece afterwards to avoid confusion.

Note how the grain lines are straight down the center of each pattern piece.

For a drapier skirt you could cut gores on the bias. However, to balance the bias, you would need an even number of gores with center front and back seams, and an 8 gore skirt would be preferable.


Note: If bias is unbalanced, it will stretch more in one direction than the other b/c lengthwise and crosswise grains differ. That is why, when you have a skirt that is bias, but the entire front is cut in one piece, over time it gets longer on one side. Were there a center front seam, and the sides balanced, it would stretch evenly.

When you cut bias pieces, corresponding left and rights must mirror each other in the layout, like left and right hands.

If these are the right and left center front pieces, this is the wrong way to lay them out. There is no point in the seam between them, they may as well be cut as one. This will be unbalanced.
This, rather, is the correct way - the pieces are mirror images. These bias pieces will balance each other.
Note: Mirroring of pattern pieces is also necessary for other bias pieces, such as undercollars. That is why there is a center back seam in an undercollar.

Of course whole books could be written on bias. Unfortunately, no one has. If only Madame Vionnet had put her expertise to paper.... Maybe bias is so fluid that it just can't be captured in that way.

More on bias, and gores, here.

Next geometric post - circular ruffles.

Serger Rolled Hem

A serger rolled hem can be done with 2 or 3 threads, depending on the capabilities of your machine. The 3-thread is generally easier to control. The 2 thread gives a more delicate finish sometimes nicer for fine sheer fabrics.

Follow the manual to set up your serger for rolled hemming. On newer machines it often just involves sliding a lever. On others it might require changing the needle plate. Additionally, if you intend to use only 2 threads, there must be a mechanism by which the upper looper is bypassed. (On my previous serger there was a small metal piece that fit into the upper looper allowing the lower looper thread to ignore it.)

Always experiment on scraps before starting on your actual piece.

Many people want to keep a record of exactly what settings work for a particular stitch. It's common for people to keep a sort of serging journal - when they find a stitch they like, they staple a piece of the serged fabric to a paper on which they've recorded all the tension, stitch length, differential feed, and cutting width settings. That's fine and actually a good idea in the beginning.

However, chances are that next time you go to make the same stitch, the settings will be a little different. So it's important to realize that when you pull out your stitch reference your settings will be relatively similar, not identical.

For example, for a 3-thread rolled hem, the lower looper tension will be higher than the needle or upper looper tension, and the stitch length will be somewhat lower than usual. The lower looper tension will not always be, say, 7. There are just too many variables to anticipate - fabric content and weave (i.e., georgette or chiffon?), cut of the fabric (true bias, partial bias, cross-grain, lengthwise?), thread content, type, and tension on the spool, needle type and size, even weather. (Yup, I truly believe the weather matters!)

Variables

Use your scraps to fine tune the settings:

• Sometimes you might want more thread coverage for a prominent roll, other times you might want the stitches to be very open and inconspicuous.
  
• You may want the smallest roll possible, in which case you can try tightening both looper tensions even further, decreasing cutting width, and/or changing thread types (mono-filament nylon, for example, is quite elastic and might squeeze the roll tighter.) A 2-thread hem will also be more delicate than a 3-thread. ~
  

• You may want an obvious, prominent roll, as for table linens or accessories. Try increasing cutting width, using a smaller stitch length, and perhaps a fatter thread, perhaps a beefy decorative thread such as perle cotton or ribbon. (More on serging with specialty threads in a future post.) You might even run some cording into the roll to give it some heft and stiffness. Remember, you're the boss. This rolled hem was done with a thick gold metallic decorative thread ~

• You can run wire through the roll (very carefully so it doesn't hit the knives) and make your own wired ribbon.
  
• You can run fishing line through the roll for a graceful, scalloped edge. (more in a future post.) ~

• You can attach lace or other trim with a rolled hem. This is an especially elegant application ~

• Run over a fold without cutting, the rolled hem makes nice pin tucking.
• Note: You can use rolled hem settings without actually rolling the fabric. The idea here is to increase lower looper tension relative to upper looper tension. The upper looper thread will then wrap completely around to the back of the fabric, giving the nice coverage of a rolled hem without the rolling. Especially useful for finishing the edges of thick decorator fabrics. You can do this over the regular stitch finger while cutting for an even edge.
  

Problem Solving

Whiskers - This is how I describe when fabric thread ends stick out from the rolled hem like, well, whiskers. It can be especially problematic on bias cuts. There are several ways to deal with whiskers (besides bleach or wax.)

• Try increasing cutting width. Having more fabric in the roll helps those fiber ends become secured inside the roll.
• Try decreasing stitch length. More thread coverage may secure the whiskers.
• Woolly nylon thread spreads over the surface of the roll providing coverage than regular thread.
• Press a fold into the edge of the fabric, then do the serged hem over the folded edge, without cutting.
  
• Run a length of straight grain fabric along the hem as you serge. Understand that this will make the roll beefier and eliminate any stretch.
  

Waving - This is when the hem edge stretches as you serge, forming waves or undulations. Sometimes you want that waviness as it's quite feminine and lacy looking. But if you want a straight edge here's what to do:

• If possible do all hemming on straight or cross grain. (i.e. for napkins or scarves.) Note: cross grain will sometimes wave when straight doesn't. Remember, cross grain is stretchier than lengthwise. If that happens, you may have to turn up differential feed on the cross grain edges only.
• Turn up the differential feed slightly. Anytime you have trouble with a fabric stretching under the serger foot, this is the thing to do.
• Use your fingers to push fabric towards the presser foot as it feeds. Just as you would on a conventional SM if you were stay-stitching.
• Try starching the edges first.

Roll comes off edge of fabric - Don't you hate when rolls get away from you??? Seriously, this is when the rolled hem just detaches from the body of the fabric. It's quite disturbing when it happens. But you can fix it:

• Increase cutting width. This in effect places the stitches further into the body of the fabric, giving them more "grip."
• Decrease stitch length. The denser the stitches, the more perforated the fabric is and the more likely it is to come apart.
• Use a smaller needle for smaller holes.
• In extreme cases, you may have to pre-fold the fabric edge and serge over the fold, as above.

A serger is worth having just for the rolled hemming. It's fast and fun and gives a very professional finish.

A (very) Quick Lesson on Bias

If you are partial to A-line or circle skirts you've probably noticed that, over time, the sides of the skirt get longer. Why?

Fabric has dramatically different properties based on the way it's hanging. Imagine one piece of fabric, 20 yards long, on a loom. (Looms aren't 20 yards long of course, but this is just a visual.)

The threads that make up the fabric go in two directions. Some are 20 yards long and go the entire length of the fabric. Those are warp threads.

The others are woven in at right angles to the warp. They are only 20 - 60 inches wide or so depending on how wide the loom is. These are the weft threads.

Warp threads are stronger and more stable (less elastic) than weft threads. When garments are made, they are generally made so that the warp threads run vertically up and down the body and weft threads, which have more give, run around the body horizontally. (This helps accommodate for that last, wholly unwarranted, trip to the buffet.)

Now, sometimes a garment is cut "on the bias." When you are watching an awards show and the stars parade up the red carpet in those drapey, flowing, form-skimming silk gowns - those are likely bias gowns. Often times they are the dresses that look like "a very simple dress." Not so - bias gowns are the most challenging to make.Why? Because when garment pieces are cut "on the bias," they have little or no stability. Bias cut fabric sections have warp and weft threads that run diagonally on the fabric. There are, then, no threads that run directly from shoulder to hem, or side to side, and stability is lost. There's no anchoring.Bias fabric stretches and slips and slides and really "morphs" every time you touch it. I tell students that sewing bias silk is like sewing water.

So...what does any of this have to do with your skewed rayon skirt? Well, the skirt is cut with those stable warp threads running down the center front. But just due to the shape of the skirt pieces being triangular, the fabric on the sides has bias qualities. Only the middle section has threads that run from waist to hem. The flared edges do not.

So, over time, it stretches out on the sides, where there are no threads anchored to the waist. What's worse, if there is no stretch in the seam itself, then the fabric near the seam stretches and the seam doesn't, leaving a ratty looking puckery line along the seamline stitching. (I can't draw this..but you'll know it when you see it.)

Note how, in the gored skirt, left, the lengthwise fabric threads can be re-distributed over the smaller gore sections. Because the skirt is cut in more sections, you can place more threads that go vertically from the waist to the hem. You achieve the same fullness, but with less bias instability. And the small amount of bias instability that is present, is distributed evenly among 6 seams (in a 6-gore skirt) rather than two, as in the skirt drawing above.

When you are making a non-gored skirt yourself, you can compensate for future stretching by letting the garment panels hang and stretch before you sew them together. It would also be wise to sew any bias seam with some stretch built it...a narrow zigzag stitch or a serged seam to avoid that ugly puckering at the stitching line if stretching occurs.

For those with RTW that has stretched, it can be re-hemmed.