Question

Which type of seam requires no seam allowance?

Answer 1

A felted or welded seam requires no seam allowance, as it joins fabrics through heat and pressure, common in performance wear and waterproof items like raincoats.

Step-by-step explanation:

The type of seam that requires no seam allowance is called a felted seam or welded seam. In felting, fibers are joined together using heat, moisture, and pressure, eliminating the need for extra fabric to be tucked or sewn in. Welded seams, often found in performance wear or waterproof items, utilize heat and pressure to bond fabrics together chemically or thermally without extra fabric. A common example of this in everyday items is heat-sealed edges in synthetic fabrics used for raincoats or outdoor gear.

Answer 2

If you do not plan to make up a toile of your pattern (in the case of pattern blocks), then there is no need to add seam allowance