Britney Moulton of Fort Collins, left, describes her hat-knitting techniques to Caroline Goosman of Boulder Shelter for the Homeless during the Loops for Love event Thursday at Longmont Yarn Shoppe.

Knitted fabrics like a scarf or socks are highly elastic, capable of stretching as much as twice their length, but individual strands of yarn hardly stretch at all. It's the way those strands form an ...