What is 'fabric grain'?

Fabric grain refers to the direction of the threads in a fabric, which is fundamental in determining how the fabric behaves and drapes. There are generally three types of grain in fabric: lengthwise, crosswise, and bias.

The lengthwise grain runs parallel to the selvage—where the fabric is finished to prevent fraying—while crosswise grain runs perpendicular to the selvage. The bias is at a 45-degree angle to both the lengthwise and crosswise grains. Understanding fabric grain is crucial for cutting patterns correctly and ensuring that garments fit well and hang properly, as the grain affects the way the fabric stretches and moves.

In contrast, the other options provide information that does not directly relate to the definition of fabric grain. The pattern on the fabric surface, the type of fabric, and the weight of the fabric material are all important aspects of fabric characteristics, but they do not define the concept of grain itself.