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Understand and Find 3 Different Grain Lines on Woven Fabric
Cotton woven fabrics are one of the easiest fabrics for a beginner to learn to sew with because of the fabric’s stability when pinning, cutting and stitching. There are 3 different Grain Lines on Fabric to learn about.
What are Grain Lines of Fabric?
Woven fabrics have Lengthwise, Widthwise (Crosswise) and Bias grain lines. Lengthwise grain lines are known as Warp threads and run parallel to the selvage edge. Widthwise grain lines are known as Weft Threads and run perpendicular to the Length grain. The Bias is an imaginary line running at a 45 degree angle to length and width grain lines.
Several different helpful accessories for making sure fabric grain lines are straight, would be either the collapsable cardboard measuring board OR a Big self healing mat, rotary cutter and clear ruler.
Lengthwise Grain and Selvedge Edges
Pre-wash the fabric the exact same way you’ll be washing your project/clothing item when it needs to be cleaned later. **Please consider the washing instructions on the end of the bolt of fabric.
The first thing you may or may not notice is that after pre-washing, is that the selvage edge of fabric may have tightened up just a bit-which is normal considering the selvedge edge is a tighter weave of fabric; that’s OK.
For a visual of the following steps- watch the video above.
You will match up selvedge edges to each other to make sure your fabric LAYS FLAT. You may need to slide selvage edges, in one direction or the other, along each other to get the fabric to lay flat. The widthwise edges of fabric most likely will NOT be lined up with each other at this point-that’s OK.
After the fabric flatness has been achieved, I like to place a few pins in the same direction, in the selvage edge area so when I move my fabric on the way to the ironing board, the fabric won’t move on me. I now like to press the fabric, getting a good TRUE pressed fold line/straight edge.

Using TRUE Folded Edge To Cut Straight Side Seam Edges If Needed
Using the TRUE/straight folded edge, line this edge up along your board. Now, If you need to, it is time to cut a straight cross-width grain edge. Using a measuring line that is perpendicular to the line your TRUE folded edge is on- use this line for cutting a perpendicular cross-wise straight edge.


After all your edges are straight, you are ready to lay out your pattern pieces on your fabric!
Understand your pattern before you start laying pieces out on the fabric!
Frequently Asked Questions
- What is On-Grain definition? Lengthwise and Crosswise threads are perpendicular.
- Can you tear fabric lengthwise or widthwise? Lengthwise-YES Crosswise- DEPENDS on how tightly woven the fabric is.
- Is straight grain of fabric the same as lengthwise grain of fabric? Both the Lengthwise grain and widthwise (cross-wise) are considered straight grain of fabric.
- What grain line runs parallel to the selvage edge? LENGTHWISE GRAIN
- What are warp yarns? The LENGTHWISE threads
- What are Weft yarns? The CROSSWISE threads
Thanks for reading and Happy Simple Sewing to You!
For any questions about this post you can contact amy@amyssewingstudio.com