Getting Fabric Straight

Why does it matter if the fabric you’re about to cut is lined up or trued or squared? And wait, what does that even mean?

Fabric is made of threads and woven fabric (as opposed to knit fabric) is woven from threads. The looms are set up with lengthwise threads (the warp) and thread is woven across these (the weft). Because of these two opposing thread directions fabric ends up having what we call, a lengthwise grain and a cross grain.

Along the length of any fabric is the selvedge (the tightly woven edge of the fabric). The lengthwise grain is the strongest grain. Fabric is cut off the loom and cut off the bolt across the width. This cut edge reveals the cross grain. The bias is not a grain. The bias is at a 45 degree angle from the length and cross grains. It is the diagonal direction of a square of fabric.The bias has the most stretch.

When laying out apparel pattern pieces for cutting you may have noticed pants patterns will run from waist to hem along the lengthwise grain and sleeves will run from shoulder to wrist along the length. Garment pieces are cut this way for drape. Drape is how a garment hangs on the body or even on the curtain rod. Fabric hangs nicely when the lengthwise grain is vertical. (Waist bands and handles are cut along the lengthwise grain too but for strength).

When pattern pieces are cut off grain the results can look a little skewed. Ever owned a t shirt that had a side seam twist forward on one side and backward on the other? That shirt was cut off grain. The cutter knew to follow the grain line printed on the pattern but the fabric itself (many layers thick in an industrial setting) was not laid out straight. This is why you want to have the fabric lined up, trued or squared before you cut your pattern out.

Read Squaring Up Fabric