Biased: Introducing Bias Cut Fabric

We talked last time about the construction of fabric and what " straight grain" means.

From Threads Magazine

Basically it means the fabric is cut along the line with either the warp grain( the long threads of the fabric) or the weft grain, (the threads going across).  Fabric is just woven threads. It's not static. The threads can easily shift within the fabric.So it can stretch, warp, or shift on you in a moment's notice.  The straight of grain fabric does that slightly. But what if you cut at a 45 degree angle across the square. The picture shows us a log of thread ends with nothing to hold them in place. That 45 degree cut is a bias cut. And since the threads aren't holding each other in place, it stretches. Not just a little bit. A lot! 

Is that a good thing? Again, nothing is  good or bad but thinking makes it so.

You may think this talk about grain doesn't matter to beginner sewers, or people making simple quilts. But it helps you predict how fabric will react as you sew it. And if you think it through, you'll understand some of the problems involved with sewing bias and some of the solutions.

Elizabeth Hartman from Oh, Fransson!

Remember how we talked about half square triangles, and how many different kinds of blocks you can cut from them? That seam across the half square triangle is bias cut. Any quilt we make with triangles or diamonds by definition has a bias seam, waiting to stretch out before your eyes. 

Before you start to panic, quilters have dealt with this from the beginning of quilting. And knowledge is power. Are you wondering why one square is bigger than the other? Pointed slightly differently? Why the seams don't match. It could be due to bias stretch. Here's some ways to control that,

From Exuberant Color

Bias coping skills

• The simplest thing to do about bias is to remember not to stretch it. Don't pull it through the machine. Don't tug it into place. Don't encourage it to stretch more than it does just in sewing.
•  Cut accurately and trim to even things out rather than stretch a seam to make it match.
• Use a walking foot to make your fabric feed evenly top and back side. A walking foot grabs fabric from both the top and the back side.
• Use pins. A lot of pins
• Don't drag your iron along the seams. Lift it. Place it. Let it steam. Repeat.

If it stretches a little, that's fine. Just don't encourage it to stretch a lot.

From Nettie at aquiltisnice

Is there an upside to bias? Actually yes there is! That curve you see on this bound edge is from cut bias strips. The bias stretches nicely to accommodate the curve. Many quilters use bias binding because that stretch leaves a smoother bound edge.

We'll talk more about bias binding next time!