Fabric Grain line:
Fabric grain or grain line refers to the orientation of the yarns in woven fabric. The warp yarns run from back to front in the weaving loom and form the lengthwise grain—often called the straight grain. The weft yarns are woven from side to side into the warp yarns and form the crosswise grain, or cross grain. The lengthwise and crosswise grains are perpendicular to one another in the loom. The bias falls along any angle to the leng thwise or crosswise grain, (see the drawing below) and the true bias is at a 45-degree angle to the straight grain. Nonwoven fabrics, such as felts, have no grain.
Fabric Grain effects they way fabric will hang and drape. There are three types of fabric grain.
- Lengthwise grainrefers to the threads in fabric which run the length of the fabric, parallel to the selvedge of the fabric.
- Crosswise grainare the threads that run perpendicular to the selvedge of the fabric or the cut edge of the fabric as it comes off the bolt.
- Bias grainis the thread line that is at a forty five degree angle to the lengthwise and crosswise grain of the fabric as it is on the bolt. The bias has stretch in woven fabric and will hang differently than a garment that has been cut on the straight or crosswise grain.
When you are working with woven fabric, the lengthwise and crosswise grain will not have any stretch. Depending on the tightness of the weave the fabric may have “give” but it will not stretch.
The Bias grain however will stretch, making the bias grain a perfect for couture areas such as covering cording to create your own piping.
Because the bias grain does react differently that the lengthwise or crosswise grain it may require special handling. For example; A skirt cut on the bias grain must hang for 24 hours before you attempt to hem it.
Although knit fabric is constructed differently than woven fabric, fabric grain is characterized the same way it is for woven fabric.
Although knit fabrics stretch, the amount of stretch may vary in the different grain lines.
Always read the back of a pattern envelope that is designed for knits and test the stretchability of the fabric with the information on the pattern envelope.