It is exciting to work on bias grain.
It transforms rigid cloth; with a set length and width, into a pliable interactive surface.
If you take a square of cloth and fold it diagonally you have the bias grain,
45° to the selvage.
Pull the corners of the triangle and it will stretch.
The space between the woven threads determines how much movement is in its structure.
A loosely woven cloth will have more “ Give “ than a tight weave.
Woven cloth is a lattice. Imagining it this way will make it easier to understand how the cloth will react on the body; how it will look if it is tight and when it is loose.
Traditionally it is used on areas that curve around the body, like the roll of a collar or sashes or ties. The other beautiful thing about the bias is how it drapes. Cloth on the bias flows - fabric on the straight grain is stiff in comparison.
Making clothes on the bias doesn't have to be difficult.
Here I would like to set out some guidelines.
Choosing the right cloth for projects on the bias is very important
I recommend a wash test.
Draw 2 rectangles around a A4 piece of paper with a wash proof pen. Then wash the sample in the washing machine. Let it dry and iron it. Then compare your cloth with the piece of paper in both directions. If the cloth remains the same , or even shrinks by the same amount you are in business. If one direction shrinks more than the other direction the project will still work as long as you cut pairs; if you don't your garment will twist.
If your fabric does shrink, wash your cloth and iron your cloth again to be sure that it stays the same- looking at YOU linen!
Linen, cotton, viscose fibres expand as they absorb water as the fibres dry out they stay extended. The expanded fibres take up more space in the weave so that the cloth is narrower and shorter. Ironing it will give you an accurate picture of how the cloth will behave.
There is a belief that cutting on the bias is fabric hungry- sometimes it is , but it doesn´t have to be.
As with every project you will get the best fabric use from cloth that is the same on both sides and can be cut parallel to the grain or at 90° to it. There is an illustration below to show you how to “ Cheat “ if you are missing a corner and want to squeeze out a pattern.
Be careful when you are cutting out. Line up the selvage of your cloth with with the edge of your table or a long ruler. If you don´t have a set square fold a piece of paper on the diagonal and use it as a guide.
I use a tailor's pen or even a felt pen- I do this because I don´t want the fabric to move.
Weigh down the pattern pieces with weights to prevent them moving .Mark all the notches and consider adding a few if your fabric is very slippery.I mark my notches with a pen spot instead of a small cut because it is easier to find them again particularly if an edge has been neatened.
Notches are a very useful tool- I would even suggest adding a few for long seams so that you know where you are. The seams are the same length- if you end up with one side longer than the other your garment will twist.
If you are sewing pieces together that are cut on different grains put the stretchier one underneath. The feed dog of the machine will stop it stretching out.
Benefits and pitfalls
The bias is dynamic in the true sense of the word.
For example you can use it for sleeves and rotate any piece 45°. The sleeve will fall beautifully and allow much more movement. I use this trick for the sleeve lining of the Stadtmantel.The outside fabric is stretchy so the lining of the sleeve should be too. I hate repairing sleeve lining . If a lining has enough “give“ it won't rip.
The bias is obliging. The front of the Stokx Rock is cut diagonally. When you sit, your body changes shape. The Bias allows a few extra centimetres so that it doesn´t feel tight when you sit. In contrast, the back of the skirt is cut on the straight. This is to prevent “seating", that baggy stretched-out look over the bottom. The Stokx Rock also has a centre back zip - because I considered it very bad design to put a zip* into a diagonally cut seam. (still do)
Joining cloth cut on different grains doesn´t need to be difficult; follow the notches and when you are sewing put the stretchier grain underneath when you sew, that the feed mechanism of the machine will ease it automatically onto the upper piece.
These styles are part of what I call the “Frank Family” a long story for another time.
What they all have in common is a diagonally cut upper back piece. This piece replaces the folds that are usually for movement.** It really works.
However the armhole will stretch and the sleeve will look odd if the section that joins the sleeve it isn´t reigned in with a band of fixing tape before the sleeves are sewn in.
Women´s clothing can be very static; cut for standing and looking nice.I have owned some of these garments, but not for long- I hate it when I can´t move.
Bindings and facings are often cut on the bias. The flexibility of bias binding allows it to curve around armholes and necklines.You will find a double broad bias facing inside the Stokx Rock, Annie Hose and Annie rock. This method is perfect for the edges of skirts and trousers because it lays flat and the doubled edge doesn´t need to be finished.
The Bias is a great until it is not- actually the bias is as it is and if you expect it to behave like the straight grain it is your mistake.
Here is a list that I don´t suggest you try unless you really want to take the red pill ***
Don´t cut bias-binding off grain.
Cut Bias binding exactly 45° to the fabric edge- otherwise it won´t roll obediently it will twist- If you find yourself in this situation either make a feature of it or cut it again.
Don´t put a zip in a bias seam. Or at least be very aware of the danger.
Even if pattern instructions tell you that you can tape your seams. The bias is where the cloth is the most flexible and you are making it inflexible. If the zip is in the centre back you will end up with a strange tail and if you put a zip on one side and not the other the dress will be asymmetrical.
Don´t expect the hem to be straight.
Circle skirts are traditionally hung up for a week or so before they are hemmed so that they can “drop”. The circle will probably keep dropping unless you store your skirt flat.
Bias-cut dresses fit differently on different bodies. If a hem is supposed to be straight ,wide hips will make it go up in the middle and hang at the sides just as narrow hips will do the opposite. To avoid this problem make your skirt deliberately asymmetrical - or make the centre front and the back deliberately different to the side lengths.
... To be continued ....
*Don´t put a zip into a seam on the bias if you can avoid it…
**I developed this idea because my customers didn´t like ironing straight folds into the back of their shirts….. Or didn´t even have irons.
*** the willingness to learn a potentially unsettling or life-changing truth, by taking the red pill, …
(The Matrix 1999)