What is the Fabric Grain?
The term fabric grain refers to the way threads are woven in a piece of fabric.The threads run two ways: lengthwise and crosswise. (Knit fabrics run on-grain too: the loops are constructed in crosswise and lengthwise fashion). You must cut on the grain so that the garment drapes the way the designer intended. Fabric grain is a topic covered first in clothing construction because it's important to the drape of the clothing. The fabric grain has give but no stretch. It runs perpendicular to the selvedge.
|The grain-line is marked with the long black arrow|
What happens if I ignore cutting on the grain?
I am an expert at this. I didn't cut on the grain all through high school, unless I was being graded on a project. Take it from me, you will soon see that there are problems.
For example, lets say you are cutting two pieces for a simple skirt. One is cut on grain and the other is not. The two pieces would then have different amounts of stretch. When you wear the finished garment, there will be a noticeable difference in the way the two pieces hang. One front piece will have stretch one way and the other piece will have stretch a different way.
Check the grain first:
All fabrics made from yarns are on grain when manufactured. Looms and knitting machines are built to construct fabrics in a grain perfect manner. However, a fabric can become off-grain during the processes of finishing (dyeing, printing, permanent finishing, and/or packaging, winding onto a bolt).
An easy way to test the fabric grain is to fold a piece of fabric in half lengthwise and pin the selvage edges together. If the fabric lies perfectly flat, the grain is perfect. When you purchase fabric, it is important to lay it out and be sure that it is perfectly flat. If it is not, unpin the fabric and tug it on opposite corners to right the grain. Try again.
Fabrics are on-grain when the lengthwise and crosswise threads are perpendicular to one another.
Be Careful with Stripes and Plaids - they may be printed on the fabric rather than weaved into the fabric. It is easy to assume the grain runs with the stripe but this is not always the case.
So measure your grain-line (the large arrow running in the middle of the pattern piece) at each end. Be sure each end of the grainline is the exact distance from the selvedge and pin that first.
Karen , from Did You Make That?, has a great pictorial tutorial on it here.