What is bias? Fabric bias vs. grain

Leggi questo post in: Italiano

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

Welcome to February 2017, which I am unofficially dubbing “Bias Month”!

I was inspired to create a whole series of lessons and tutorials all about bias for my Learn to Machine Sew course by my newest sewing pattern in the works, which uses bias strips in two different ways. Besides this lesson on fabric bias vs. fabric grain, there will also be lessons, with cool practice projects, on:

How to sew bias tape to an edge
How to sew a long strip of bias tape
How to bind corners and curves with bias tape
How to hem with bias tape

Save this Cucicucicoo post on Pinterest

But first, you might be asking yourself, what IS fabric bias?

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

As I explained in one of the very first Learn to Machine Sew lessons, “Understanding Fabric,” all fabric has a grain. The type of grain depends on the type of fabric, but most it’s pretty straightforward for most woven fabric. The straight grain runs parallel to the fabric selvedge and the cross grain runs perpendicular to the selvedge. If the fabric has no elastic fibers in it, woven fabric does NOT stretch along the grain and patterns are therefore usually cut along the grain to avoid distortion.

The bias grain runs in two directions at a 45° angle to the selvedge, and therefore also to the straight and cross grains.

Fabric can be cut along the bias for many different reasons. Let’s take them one by one.

Why use the fabric bias?

1. The bias is flexible and stretchy. Like I said before, woven fabric without any elastic fibers does not stretch even a millimeter. That is, unless, you use it along the bias. Bias tape, long folded strips of fabric cut on the bias, is frequently used in garment sewing to bind or hem curved edges because it has enough give to be worked around non-straight edges without any creasing or distortion. This is also the reason why neck ties are sewn on the bias; that way they can curve around the neck and be knotted smoothly.

We’ll talk more about bias tape later. This short video shows how just rotating a piece of fabric 45° changes the way it behaves:

2. Fabric cut on the bias doesn’t fray. Sure, tiny threads may come loose, but you’ll never see whole long threads come out.

3. Fabric cut on the bias drapes more nicely. Remember when I wrote about fabric drape? Very often women’s garments are cut and sewn on the bias so that they fall more fluidly around the curves of the body, often accentuating feminine curves. The following image from Sarah Image Fit shows some great examples of garments using the drapey quality of bias to their advantage.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip.

Image source: Sarah Image Fit

4. Fabric cut on the bias can look really cool. This is often true in the case of fabric with a pattern. Stripes can be put together to create chevrons (like in the shirt in the image above), and other geometric designs can be juxtaposed, creating a really interesting aesthetic effect, as you can see below.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

Cutting patterns on the grain or on the bias.

Pattern pieces, such as my soon-to-be released Field of Flowers costume shown in the following pictures, always have an arrow or line to show the grainline. This will usually be a vertical line, meaning that the pattern piece must be cut along the grain, which is the case of the Field of Flowers leaf.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

When a piece needs to be cut along the bias, you’ll see that this line is at an angle, usually a 45° angle, which is the angle of greatest stretch and flexibility. This is the case in the Field of Flowers neck binding and strap piece, seen above.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

When positioning the pattern pieces on the fabric, you must make sure that the grainline marking goes in the direction of the fabric’s straight or cross grain. Therefore a pattern that is to be cut along the bias will most likely need to be positioned diagonally across the fabric.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

The one bad side to this is that you end up wasting some fabric because of the oblique positioning. As you can see above, there’s a lot more unused fabric with the Neck Binding and Strap piece positioned correctly than there would be if it were positioned along the grain.

Cutting bias strips from fabric.

Whole pattern pieces can be cut on the bias, but you will usually use bias in the form of bias tape, which are strips of fabric cut on the bias and folded lengthwise. Like I mentioned before, these are usually used for binding curved openings. I will show you in a later tutorial how to make very long strips of bias tape with or without a special bias tape maker, but for now I’ll show you how to make your own short strip of bias tape, just to understand how it works.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

It is MUCH easier to cut bias strips with a rotary cutter*, cutting mat*, and quilting ruler*. (Affiliate links to the same products that I use and that you see in these pictures.)

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

The cutting mat has a printed grid and also lines at various angles. The quilting rule also has a grid, so with these tools you can easily and quickly cut straight lines at a 45° angle whatever distance from each other that you want. Here’s how:

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

1. Position the edge of the fabric along the 45° line, as seen above.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

2. Position the quilter’s rule so that the top edge is against one of the horizontal lines. In the picture above, I lined up with the 10 cm line. Cut across with the rotary cutter.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

3. Move the quilter’s rule up however many centimeters width you need and make another cut. And there you have your bias strip!

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

Bias strips are generally folded into bias tape before sewing. There are two types of bias tape: single fold and double fold.

Single fold bias tape has the outer long edges folded in to the center of the fabric’s wrong side. The width of the bias tape is considered from one fold to the other. So if I fold both edges of the 6 cm wide strip that I just cut to the center, I will end up with 3 cm single fold bias tape. This type of bias tape is generally used for hemming or for simply sewing on top of fabric for decoration.

Double fold bias tape is single fold bias tape folded in half where the two fabric edges meet in the center, shown in the picture above. So my 6 cm wide bias strip, which was 3-cm single fold bias tape, would become 1.5-cm double fold bias tape. Double fold is used much more frequently, usually for binding curved edges, but it can be used in many ways, which I will talk about another day.

How to make double fold bias tape.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

1. Heat up your iron with the highest heat and steam settings possible and iron the bias strip flat.

2. Iron the strip in half lengthwise, wrong sides facing.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

3. Open up the fold from step 2 and iron the top long edge down until it reaches the center fold. Do not go beyond the center fold!

4. Iron the bottom long edge until it almost reaches the center fold. The best double fold bias tape has one side that is ever so slightly wider than the other, just a millimeter or so. If this is too complicated, don’t worry about it, but it will make for more professional-looking binding, which we will get to in another lesson.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

5. Fold the strip back in half along the original center fold and press flat.

That’s it! Notice in the picture above how one side of the double fold bias tape sticks out from under the other. That is because the second edge didn’t get folded all the way to the center in step 4.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

Your double fold bias tape can be unfolded to show the wrong side of the fabric on the inside of the folds. The raw fabric edges are encased inside the folds.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

If you need to make single fold bias tape, you just fold both raw long edges over by 1/4 of the strip width. So, in the case of a 4 cm wide strip, fold each long edge inwards by 1 cm for 2-cm single fold bias tape. This is really easy with the hemming trick that I showed in my How to Sew a Perfect Hem lesson.

What's the difference between fabric grain and fabric bias? Learn all about them, when it's useful to cut on the bias, and how to cut a bias strip on www.cucicucicoo.com!

Don’t forget to come back in the next few days and weeks for lots of other great tutorials for techniques and cool projects using bias!

Save this Cucicucicoo post on Pinterest

Learn to Machine Sew with Cucicucicoo: a free sewing course for beginners

This lesson on fabric bias is part of the syllabus of Cucicucicoo’s Learn to Machine Sew beginner’s sewing course! Don’t forget to share pictures of your work on Facebook or the Cucicucicoo Creations Flickr Group!

Related Posts Plugin for WordPress, Blogger...
Share via:
Facebook Twitter Pinterest Plusone

12 Responses

  1. Wow Lisa, adoro la tua rubrica dedicata al cucito. Sugli sbiechi ho sempre avuto problemi ma questa volta credo che imparerò moltissimo! Baciotti

    • Ciao Elisabetta! Infatti, molte persone hanno problemi con lo sbieco, ma è una tecnica utilissima. Torna la settimana prossima per trovare le prime lezioni su come usarlo! 🙂

  2. Che bello finalmente …….. Tante lezioni sullo sbieco, sono contentissima, aspetterò con trepidazione, grazie Lisa.

    • Dopo tutto questo tempo, era ora che trattavo lo sbieco, che è un mistero per tanti, ma è tanto utile! Aspetterò le tue reazioni alle prossime lezioni, Marea! 🙂

  3. Great post! I’ve got a Craft Gossip post scheduled for tomorrow afternoon that features your post about fabric bias: http://sewing.craftgossip.com/?p=91678 –Anne

Trackbacks

  1. […] What is bias? How to sew bias tape to an edge (coming soon) How to sew a long strip of bias tape (coming soon) How to bind corners and curves with bias tape (coming soon) How to hem with bias tape (coming soon) […]

  2. […] What Is Bias? Fabric Bias Vs. Grain, by Cucicucicoo […]

  3. […] What is bias? How to make bias tape with a bias tape maker How to sew a long strip of bias tape (coming soon) How to hem with bias tape (coming soon) […]

  4. […] What is bias? How to make bias tape with a bias tape maker How to sew a long strip of bias tape (coming soon) How to bind straight and curved edges with bias tape How to hem with bias tape […]

  5. […] easy to understand sewing tutorial about fabric bias by the talented Lisa at Cucicucicoo. This guide, complete with helpful photos teaches you about […]

  6. […] plus a burp cloth. All styles and variations can be sewn in two different methods, with or without bias tape, making it absolutely perfect even for beginner […]

  7. […] Normally making just a little bit of bias tape is annoying because you have to cut diagonally into your fabric. But I’ll give you a little time- and fabric-saving tip: for this project, you don’t need to go around any curves, so you can cut your bias tape on the grain, not on the bias. So, instead of cutting a strip diagonally, just cut it parallel to the fabric selvedge! I’m going to continue calling it “bias tape,” but what I used isn’t technically bias tape, although it’s used in the same way. (Learn more about how bias and grain are different here.) […]

Speak Your Mind

*

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close