If you look really closely at your fabric, there are little lines of thread that run perpendicular and parallel to the selvage. These are your grain lines.
There are different names for whether the grain line is running perpendicular or horizontal to the selvage:
- Threads that run the length of the fabric are following the warp grain.
- Threads that run the width of the fabric – from selvage to selvage – are known as following the weft grain.
You might want to just start throwing down your pattern pieces and cutting out your material, but it’s not just as simple as that. The grain lines are used to line up the patterns for your garment; if it isn’t used you might find that the front of your blouse has vertical stripes whilst the back has horizontal stripes. If the fabric has a texture such as faux fur, it is referred to as having a nape. The colour or texture may very well look different when viewed or brushed in different directions. The colour or sheen may differ, or the texture might vary slightly.
You’re fabric might look the same in any direction, but it definitely won’t act the same in every direction.
Fabric stretches more along the bias than it does on the grain; overtime this might cause your garment to become lopsided, or you might even end up with one sleeve longer than the other.
The selvage is the finished edges of fabric, used to stop fabric from unravelling or fraying whilst still on the bolt. Often manufacturers will add printed information such as their company name and fabric type, along the very edge of the selvage.
The selvage is incredibly important – and helpful – as a guide to determining your grains. The selvages will always run the length of the fabric.
The term selvage, also spelt selvage, have been etymologically linked to the 16th century term “self-edge”, where the selvage edges are finished.
In many cases the selvage is discarded. Modern day mass production in the ready-to-wear industry has shown the ability to use selvages in the garments, decreasing the time it takes to produce a garment. However many home sewers prefer to not include the selvages as overtime they can shrink and pucker, distorting the ideal appearance of a garment.
The bias is at a 45-degree angle to the grain.
“On almost all fabrics, the bias cut stretches. It has the most give, and the most stretch. Try it on a non-stretch fabric – pull it vertically, horizontally, and then diagonally. The weave should stretch only on the diagonal, either slightly or a bit actually. While cutting ont he bias can mess you up if you’re trying to make a simple blouse or jacket, this can be very helpful for certain garments and is used a lot in haute couture to improve the garment fit and drape. It reduces drag lines and makes a more comfortable fit, but since you’re cutting the piece diagonally, it tends to take up more space and thus more fabric. Some full length dresses need TWICE as much fabric than they would if they were cut lengthwise, equalling several yards needed in fabric, up to 6 or even 9.”