The grainline is a line marked on a pattern piece indicating how it should align with the fabric's grain (warp threads). Correct grainline placement determines how a garment hangs and wears.
Why Grainline Matters
Cutting off-grain causes garments to twist, drape poorly, and develop uneven hems - problems that often get worse after washing. The grainline arrow is one of the most important markings on any pattern piece.
Lengthwise vs Crosswise Grain
- Lengthwise (warp): strongest direction, least stretch - most pattern pieces are cut on this grain
- Crosswise (weft): slightly more give, used for specific pieces
- Bias (45 degrees): maximum drape and stretch - used deliberately for fluid garments
Marking Grainlines
The grainline is drawn as a long straight arrow on the pattern piece. When laying out the marker, the arrow must run parallel to the fabric's selvage edge - the finished edge that runs along the warp.
FAQs
- What happens if I ignore the grainline?
- Garments twist, hems go uneven, and drape suffers - especially after washing.
- Can grainline be intentionally off?
- Yes - bias cutting is deliberate off-grain for drape. But it must be intentional, not accidental.
- How do I find the grainline on fabric?
- Pull a thread to find the straight grain, or align with the selvage edge.
Glossary: see the full fashion glossary for more apparel industry terms.