Grainline refers to the direction of threads in woven fabric:
- Lengthwise grain (parallel to selvage) – strong and less stretchy.
- Crosswise grain – has more give.
- Bias grain (45° angle) – maximum stretch and drape.
Drape is how fabric hangs and flows, affecting the final garment’s silhouette.
Stretch comes from fiber content (like spandex) or fabric structure (like knits). Choosing the wrong grain or stretch can ruin a design’s fit.