False-colour scanning electron micrograph (SEM) of a velcro hook. A common fastener, velcro is a nylon material manufactured in two separate pieces, one with a hooked surface (bottom) & the other with a smooth surface made up of loops. The loops are loosely woven strands in an otherwise tight weave. The hooks are woven into the fabric & then cut. When the two surfaces are brought together they form a strong bond. Magnification: x20 at 6x4.5cm size.