Is it Bias or Unbiased? Fabric Cuts That Is!

Greenhouse Fabrics is proud to work with many talented upholsterers. Today we are excited to host guest blogger and upholsterer, Kimberly Chagnon. Kimberly Chagnon is the owner of Kim's Upholstery in Greenfield, Massachusetts where she is well-known for her upholstery services as well as her online presence in the upholstery community. You can find Kim sharing her expertise through her online upholstery class or YouTube channel with over 46k subscribers and 6 million views! Read below to discover her upholstery tip of the day. 

written by Kimberly Chagnon 

Upholstery is a craft in which something bias or unbiased can make a significant difference in the outcome of your project.  We often hear the term “bias cuts” when referring to welting or cording.  You can ask 10 upholsterers if they always cut their cording on the bias or not and you will probably get a 50/50 split. In my workroom, it is extremely rare that I do not cut the cording on the bias. I typically only cut straight of grain cording when I am trying to match a large stripe. 

Wing chair with bias cuts inside back the cushion 

What is a bias cut? You may ask.  The bias is when cutting the fabric at a 45 degree angle from the selvage edge.  If you take a 54” wide piece of upholstery or decorator fabric and fold the squared off cut edge to run parallel with the selvage, you have created that angle.  The bias of the fabric has more stretch or give than the straight of grain.  For example, if you pull on the bias, you can easily gain an inch or more in length but if you pull on the straight of grain, it barely affects the fabric’s length.  Doing this manipulation will show you just how much the bias can affect the behavior of your fabric cuts! For instance, when sewing cording into a cushion the bias cut cording will often times behave more fluid like and flow much more smoothly around the corners, giving a nice square look to your finished project.  Have you ever seen a cushion or pillow with an edge that is wavy and looks more like bacon?  This is often caused by cording that was cut on the straight of grain.

Blue paisley wingback chair 

Bias sewn arm covers 

Speaking of cushions, let’s talk about T-cushions or cushions with a curved side.  They are also cuts that can be considered bias.  Fabric doesn’t necessarily have to be at an exact 45 degree angle to be affected by the bias. If you have ever sewn these types of cushions, I am sure at one time or another you’ve experienced one side of your cushion appearing to have grown. This is caused by the elastic behavior of a bias cut fabric.  It’s not a fun time, but it happens.  By paying careful attention to the handling of fabric while you sew, you can easily avoid the need to pull stitches and tame the bias behavior. 

Channel back with T-cushion bias cuts 

Another way the bias is helpful is in the upholstering of a piece that has curves.  If you have ever worked on a wing chair you will know that the elasticity of bias is our friend.  When you are attaching the inside wing fabric you know it is necessary to make relief cuts that allow the fabric to easily stretch around the curves and give your wing fabric a nice smooth finish. In this case, the bias stretch allows you to get the fabric tight which eliminates all wrinkles. 

Inside arm bias of a wing chair 

So the next time you are working with a bias cut fabric, give it a tug on the bias cut side and see just how different the fabric behaves compared to a straight of grain cut!

Red Victorian chair upholstered on bias inside back 

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