What type of seam finish is used to prevent fraying on raw edges?

To prevent fraying on raw edges of fabric, several seam finishing techniques can be used, and the correct answer encompasses all of the listed methods: zigzag stitch, binding, and overlock stitch.

• Zigzag stitch - The sewing machine stitches in a side-to-side pattern along the raw edge, enclosing the loose threads and preventing them from unravelling. It is the most accessible method since it requires only a standard sewing machine.
• Binding - A strip of fabric or bias tape is folded over the raw edge and stitched in place, completely encasing the edge. This produces a neat, durable finish and is often used on visible edges such as necklines and armholes.
• Overlock stitch - Produced by a serger (overlocker), this stitch trims the fabric edge while simultaneously encasing it with interlocking threads. It is the fastest and most professional method for finishing seams in garment manufacturing.

Since each of these techniques is a valid and widely used method for preventing fraying on raw edges, no single option is more correct than the others. The answer that includes all three is the most complete and accurate response.