New scientific evidence of trade in raw materials and finished goods for the knitted textile trade is emerging from a study of more than 100 extant knitted caps from the 16th century. These long overlooked archaeological data are being re-excavated from museum archives for analysis in innovative ways. The caps are recorded in European collections as having been shipwrecked, deliberately concealed, preserved in peat bogs, or discarded as beyond use. Many were unearthed during construction work in cities, during building renovations or discovered on the seabed in far-flung locations across Europe – as far north as Norway and as far south as Croatia. Nevertheless, they show remarkable similarities in the materials used and methods of construction employed. A preliminary study recorded rudimentary measurements and identified some key patterns in the data, including a typology of early modern men’s knitted caps. Initial results from more recent biomolecular investigative techniques including strontium isotope analysis, which compares soil samples with archaeological material, indicate the land from which the knitted yarn was sourced. Contemporary evidence from documentary sources suggests labour for knitting the caps was organised in proto-industrial settings. Import/export accounts at northern European ports demonstrate how far knitted caps travelled from their places of production to potential purchasers. The knitted caps represent an astonishing body of evidence for trade in ordinary men’s clothing given the paucity of extant garments available from the era and demonstrate the swift expansion of knitting as a key technological innovation of the 16th century.