The warp direction refers to the threads that run the length of the fabric. This is also known as the machine direction because it's the direction the threads run on the loom. ... The fill, or weft, refers to the yarns that are pulled and inserted perpendicularly to the warp yarns across the width of the fabric.

How can you tell warp and weft direction?

In checks, if you find one colour with odd numbers of threads, it is warp. Then it is easy to determine warps as parallel yarns with selvedge is warp. And yarns those are perpendicular to the selvedge are weft or filling yarn.

Which way do weft yarns run?

In weaving, lengthwise yarns are called warp; crosswise yarns are called weft, or filling. Most woven fabrics are made with their outer edges finished in a manner that avoids raveling; these are called selvages. They run lengthwise, parallel to the warp yarns.