Grandma was just making a sweater. Or was she?
During World War I, a grandmother in Belgium knitted at her window, watching the passing trains. As one train chugged by, she made a bumpy stitch in the fabric with her two needles. Another passed, and she dropped a stitch from the fabric, making an intentional hole. Later, she would risk her life by handing the fabric to a soldier—a fellow spy in the Belgian resistance, working to defeat the occupying German force.
Whether women knitted codes into fabric or used stereotypes of knitting women as a cover, there’s a history between knitting and espionage. “Spies have been known to work code messages into knitting, embroidery, hooked rugs, etc,” according to the 1942 book A Guide to Codes and Signals. During wartime, where there were knitters, there were often spies; a pair of eyes, watching between the click of two needles.
When knitters used knitting to encode messages, the message was a form of steganography, a way to hide a message physically (which includes, for example, hiding morse code somewhere on a postcard, or digitally disguising one image within another). If the message must be low-tech, knitting is great for this; every knitted garment is made of different combinations of just two stitches: a knit stitch, which is smooth and looks like a “v”, and a purl stitch, which looks like a horizontal line or a little bump. By making a specific combination of knits and purls in a predetermined pattern, spies could pass on a custom piece of fabric and read the secret message, buried in the innocent warmth of a scarf or hat.
