Patchwork & Quilting - The Importance of Fabric Grain

In patchwork and quilting, understanding fabric grain is helpful in achieving the results you want in your finished quilts. What exactly is fabric grain? In woven fabric, threads are what comprise the grain.

The Lengthwise Grain - Warp Threads

Long threads form the lengthwise grain in fabric. These threads are the warp threads and run parallel to the selvage. Fabric has the least give on the lengthwise grain.

The Crosswise Grain - Weft Threads

The shorter threads that make up the crosswise in the fabric are the weft threads. These threads run perpendicular to the warp threads and selvage. Fabric has slightly more stretch on the crosswise grain than on the lengthwise grain.

Selvage

The lengthwise bound edges of the fabric, is the selvage. Many times the selvage is printed with the name of the fabric, the manufacturer and coloured markings. These coloured markings can be helpful in selecting coordinating fabric.

Bias

The diagonal of woven fabric is the bias. The true bias is at a 45° angle to the selvages. In quilting, any cut that is not along a straight grain is referred to as a bias cut. Even without selvages, you can find the bias by stretching the fabric slightly. The bias is quite stretchy.

Straight Grain

Pieces cut parallel to the lengthwise or crosswise grain are straight grain cuts. These pieces are less likely to stretch out of shape than pieces cut along the bias, as there are no threads along the bias to keep it stable.

Becoming familiar with how fabric stretches will enable you to identify lengthwise and crosswise grain in scrap patches with no selvages. This is handy as quilters end up with lots of remnants.

To test your fabric, cut a small square with edges parallel to the straight grains. Tug on the fabric. Check how it feels and looks when you pull one way, then compare this to how it feels when you tug in the opposite direction. Do you feel a difference? The crosswise grain will have a bit for strength. Now yank on the piece diagonally from one corner to the other. This is the bias and you would have felt quite a bit of stretch. If you pull hard enough you will end up distorting the square of fabric.

Now that you are familiar with fabric grain, and how to determine the direction of the grain in material, you may still be wondering why you need to know this.

Why is the grain important?

1. Cutting you fabric squares with edges along the straight grain will minimize stretching during measuring, marking, cutting and sewing.
2. Quilt borders and sashing, are best cut along the lengthwise grain of fabric. You want the least stretch for these pieces to support and aid in squaring up blocks and quilt tops.
3. Triangles will always end up with at least one bias edge. Knowing which one is the bias edge will allow you to plan the placement of the patch, so you are able sew to a straight grain piece where possible.
4. Bias cuts are easier for turning under in curved appliqué shapes.
5. Creating strips for appliqué using bias cuts makes it possible to do curves in stained glass and other bias appliqué.
6. Stretchy bias strips are also great for use in binding a quilt with curved edges.

Establishing which way the grain runs will allow you to plan you project for a professional result.