What is Selvage, Grain & Bias - Sewing Terms Explained

What is selvage, grain and bias? These three words, selvage, grain and bias, look as if they have no real relationship with each other. However, in the world of fabric, they are connected and knowing about them will help with purchasing fabric and ultimately cutting and sewing more effectively. So let's learn about what is selvage, grain and bias. Here is an overview image so you can start to familiarize yourself with the terms before we get started.

What is Selvage?

So what is selvage? Selvage is the self-finished edge of the fabric and often has the defining information about the fabric printed along the edge.

Note: There are two ways to spell selvage - selvedge (British English) or selvage (American English).

Fabric is woven and in the weaving process, it is the threads of the fabric that create the selvage. The fabric is created with a warp thread that runs the length of the fabric and the weft threads that run across the fabric and turn at the ends. The turning point is where a tighter weave is created to stop fraying and this is the selvage.

Knowing what is selvage helps to understand important information about the designer of the fabric and the colorways used in creating the pattern of the fabric.

You will see the selvage on the side of the roll of fabric when it is rolled up onto a bolt ready to sell in the shops. Quilting fabric is usually folded in half and wound onto the bolt with the selvage on one side and a fold on the other.

The selvage can also tell the seamstress about the color code used in the creating of the fabric as well as the factory it originated from. This is very helpful if you like to make quilts because the color dots on the selvage will help to match up against other fabrics for your quilt. It can also be useful for choosing thread colors.

When the fabric is measured, it is cut from the bolt by cutting perpendicular to the edge of the material leaving the selvage alongside each side of the cut fabric. Now we know what is selvage, it is on to learning about fabric grain.

What is Fabric Grain?

The grain of the fabric is an important part of the cutting process. Each pattern piece needs to follow the grain in some way. Following the grain, that is the way the threads run, is very important for well-fitting garments.

The straight grain is always marked on the pattern pieces and this directional arrow has to follow the same straight grain of the fabric. The warp of the fabric runs parallel with the selvage and is the stronger straight grain. The weft is perpendicular to the fabric and is weaker but still a straight grain.

The warp of the fabric runs parallel with the selvage and is the stronger straight grain. The weft is perpendicular to the fabric and is weaker but still a straight grain.

Here is an example of a cutting layout with the fabric pieces placed on the grain.

Further Reading: Cutting Fabric and Fabric Grainline

Finding the True Grain

If you are not sure of how to find the true grain lines, then snip into the fabric about 1 inch (2.5cm) on the selvage and tear the fabric across and see how the fabric has frayed along the torn edge.

After that pull out the top threads until all the cross threads are in the same line. This is then the straight edge on the fabric with the selvage running up the side. The edge that is cut at the store is not always straight.

What is Fabric Bias?

Finding the bias of the fabric is very important too. The bias is found on the 45-degree angle made when you fold the corner of the fabric across to the opposite edge. The line made following that angle is the bias.

what is bias — What is Selvage? What is bias?

The bias cut of the fabric is stretchy and useful for cutting your own bias tape to neaten or trim a raw edge.

Bias tape is fabric that has been cut on the bias to form strips. The stretchy quality of the bias tape makes it suitable to neaten curved edges such as necklines and armholes. Store-bought bias tape can add contrast or make piping.

There may also be a pattern that requires a piece cut on the bias. The arrow of the pattern will indicate the crossways direction to lay out the pattern. It will be necessary to know how to lay the pieces out as the flared effect achieved with bias cut pieces will be lost if the pattern is cut on the straight edge.

What is Selvage, Grain, Bias - In Conclusion

Knowing and understanding what is selvage and these three terms will assist with fabric purchases as well as cutting and trimming a garment. It is useful to know about the way fabric works and understand what a warp and a weft are as well as the selvage and grain as this is how fabric is made. The added understanding of the bias completes the three terms used to define fabric and how to take the right direction to use your fabric to the best advantage.