top of page

How to: Understand the grain of fabric

The grain line plays a pretty key role in garment construction with the potential to influence the fit, appearance, and stability of garments.

This article is a paid-for post, and I have received compensation for writing and publishing this content. This post was originally featured on The thread. The opinions expressed in this article are my own and are based on my personal experience. Any sponsored content will always be clearly identified as such.

Have you ever experienced the discomfort of wearing a garment that hangs awkwardly or twists unexpectedly? Or, have you had the frustration of laundering a particular garment only to find that it has shrunk or grown unevenly?

These annoying problems often come from the fabric’s grain alignment. This little detail has a big impact on how our clothes fit, look, and hold up over time. Understanding this concept will go a long way in ensuring we create garments that we are happy with.


A wrap-up of this article


What is the grain line?

The grain line of fabric refers to the direction of its yarns relative to the selvedge edge*.

There are three main fabric grains:

  1. Lengthwise or straight grain: Aligned with warp yarns* parallel to the selvedge, providing strength and stability.

  2. Crosswise grain: Formed by weft yarns* perpendicular to the selvedge, offering flexibility and stretch.

  3. Bias grain: Running at a 45-degree angle across the fabric, providing the most stretch and drape, being ideal for creating garments with fluid and natural movement.

Why not experiment with a small piece of fabric in order to understand how it stretches in different directions along the various grains?


How to position the grain?

When working with fabric the choice between cutting with or against the grain can have a significant impact on the overall performance and appearance of a garment. Therefore, I recommend taking into considering the following:

  • The pattern: Sewing patterns include grainline arrows. To ensure the grainline is parallel to the selvedge, start by measuring from one end of the grainline to the selvedge, and pin the pattern piece and fabric near the arrowhead. Then, measure from the other end of the grainline to the selvedge, making sure the distance is equal, and pin in place.

  • The grains behaviour:

  • The lengthwise grain provides stability and strength, therefore it is suitable for vertical elements like centre fronts and backs.

  • The crosswise grain offers more stretch and flexibility, being ideal for areas requiring movement like sleeves or bodice width.

  • The bias grain provides the most stretch and drape, being suitable for fluid designs or areas that need to conform to curves.

  • The fabric: Aligning the grain properly will help ensure a cohesive appearance when working with fabrics with a pattern (e.g. stripes or checks) or nap.


How do you identify the grain line?

To identify the grain line of your fabric, start by looking for the selvedge edge*, which runs along the length of the fabric parallel to the lengthwise (or straight) grain.

If the selvedge has been removed (perhaps you’re working with an off-cut piece), here are some methods to help you identify the grain approximately:

  • Conduct a simple pull test:

    • The direction which has the most stretch would represent the bias.

    • The opposing 45-degree angle would be the lengthwise/straight grain (least stretch) or crosswise grain (a little stretch).

  • Tear test: Make a small snip and tear the fabric. If it tears in a straight line, it’s likely along the grain line.

  • Follow the print or weave: Use any print or weave patterns to visually identify the grain.

As mentioned previously, I would describe these methods as approximates, as they don't provide as precise a guide line as the selvedge edge.

The fabric grain directly impacts how fabric behaves during construction and wear. Therefore, understanding grain alignment will go a long way in ensuring that you create well-fitting, durable garments that retain their shape and appearance over time.



Selvedge edge: The narrow and tightly woven edge of the fabric that runs parallel to the lengthwise grain. The selvedge is created during manufacturing to essentially stop the fabric from fraying and unravelling. The selvedge edge acts as a reference point for identifying the direction of the fabrics grain, often being utilised to measure and align pattern pieces.

Warp yarns: Positioned lengthwise on the loom before weaving begins, forming a sturdy foundation for the fabric. Warp yarns run parallel to the fabric's length and provide strength and stability to the woven fabric.

Weft yarns: Run horizontally, perpendicular to the fabric's selvedge edge, creating the crosswise lines. During weaving, weft yarns are interlaced over and under the warp yarns, filling the gaps between them. These yarns offer greater flexibility in shaping the fabric's design compared to the warp yarns.

Please get in touch or leave me a comment. I would love to know if you found this article helpful.

Thanks for reading.

Emma xx

This is a personal blog. Any views or opinions contained on this site are my own. Unless stated otherwise, I am not affiliated with any brands, products, or organisations mentioned, and do not receive any sponsorship, payment, or other compensation for any of the content on this site..

33 views0 comments


bottom of page