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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.

Have you ever experienced the discomfort of wearing a garment that hangs awkwardly or twists unexpectedly? Maybe you have had the frustration of laundering a particular item only to find that it has shrunk or grown unevenly? These sorts of issues may stem from a crucial aspect of garment construction – the proper alignment of fabric grain.

The grain line, which runs parallel to the selvedge (more on this later), plays a pretty key role with the potential to influence the fit, appearance, and stability of garments. Therefore, gaining an understanding of the concept is highly valuable and will go a long way in ensuring you create garments that you are happy with.

That's precisely why I've created this post. I will explain the concept of fabric grain, how it can impact your sewing project, and offer guidance on identifying and working with it effectively.


A wrap-up of this article


What is the grain line?

The grain line of fabric refers to the direction of the yarns in relation to the selvedge edge*, of the fabric.

There are three main fabric grains:

  1. Lengthwise or straight grain: This is made from warp yarns** and runs parallel to the selvedge edge of the fabric. Warp yarns form the sturdy foundation of fabric, therefore cutting on the lengthwise grain provides strength and stability. Generally speaking, most garments are cut on the straight grain.

  2. Crosswise grain: This is made from weft yarns*** and runs perpendicular to the selvedge edge of the fabric. Cutting fabric along the crosswise grain provides greater flexibility and stretch.

  3. Bias grain: This runs at a 45-degree angle to the lengthwise and crosswise grains, running diagonally across the fabric. Fabric cut on the bias has the most stretch and drape making them ideal for creating garments with fluid and natural movement such as skirts and dresses, or a hanging cowl style neckline. When working with the bias, it's crucial to select fabrics known for their excellent drape characteristics, such as tencel.

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

Tip: To assess your fabric's suitability for cutting on the bias and achieving a nice drape, consider conducting a simple hanging test. Begin by drawing a square, perhaps 10cm by 10cm, and rotate it 45 degrees to create a diamond shape. Repeat this process with a piece of the fabric, ensuring it ends up on the bias. Pin the fabric at the top corner of the piece of paper and let it hang overnight. Observe how much of the square is visible. If the fabric is still covering the square, it is probably too stiff. If the fabric has fallen, revealing the paper, and created a nice flounce, then it is probably suitable for use on the bias.


Why is the grain line important?

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.

If you are working with a sewing pattern, you can simply follow the convenient grainline arrows that will be included on all the pattern pieces. This will ensure the fabric is aligned perfectly and as intended, while also ensuring:

  • Greater stability and durability: The fabric will be less likely to distort during wear and laundering, the seams and edges will be stronger, and their will be less risk of stretching.

  • Drape and fit: The fabric will hang in a more flattering and natural way, increasing the likelihood of achieving the intended silhouette and a well-fitted garment.

  • Pattern alignment: Matching patterns (e.g. stripes or checks) or ensuring the nap runs in the correct direction will become easier, allowing for a smooth and cohesive appearance across seams.

Tip: To ensure the pattern piece is parallel to the selvedge, begin by measuring from one end of the grainline to the selvedge and pop a pin through the pattern piece and fabric (right near the arrow head of the grainline). Measure form the selvedge edge to the other end of the grainline ensuring it is equidistant and pin in place.

There are instances where working against the grain will provide the desired effect, being part of the design. Therefore, it is imperative to consider the characteristics of the fabric, the pattern requirements, and the elements of a design when making decisions regarding the grain.


How do you identify the grain line?

In order to identify the grain simply look for the selvedge edge* of the fabric. This tightly woven edge runs the length of the fabric in the same direction as the grain.

If you are working with a piece of fabric and the selvedge has been removed (maybe you are working with an off-cut piece of fabric) there are a few things you can try in order to (approximately) identify the grain of the fabric:

  1. Pull (gently) diagonally: You could try pulling your fabric piece at a diagonal (holding at opposite corners). The fabric may naturally stretch more in one direction than the other which may help to identify the bias, with the opposing 45 degree angle being the straight grain.

  2. Pull (gently) horizontally: Similar to the above method, with the direction with less stretch likely being the straight grain.

  3. Tear test: Depending on the composition of the fabric, you could try making a little snip and tearing the fabric, following the direction that tears more naturally. If this follows a straight and even line, it may be your grain line. You can always repeat to check.

  4. Follow the print or weave: If the fabric has a prominent print or weave pattern, you may be able to identify the grain visually.

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



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. 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.

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