A darning mushroom or egg is a small, hard handheld tool placed inside clothing to stretch the fabric and provide a stable surface when repairing holes or worn-out areas. They create tension by holding knitted or woven fabric taut so your stitches stay neat and flat. They also protect your hands by sitting underneath the hole so you don't accidentally poke your fingers with the needle.
By preserving the natural curve of garments like socks or sweaters while you weave a patch over the damage, this kind of aid can help you to create a seamless and tidy mend. Darning eggs, as the name suggests, are egg-shaped with a small surface area which makes them ideal for tight spaces like the toes and heels of socks. Similarly darning mushrooms are mushroom-shaped with a handle and a broader, flatter cap and are best for larger areas like sweater elbows or flat fabric.