A tech pack (technical packet) is the absolute blueprint of a garment. It serves as the primary contract between a designer and a garment manufacturing factory. A professional sportswear tech pack includes 2D vector flat drawings, a Bill of Materials (BOM) specifying fabric GSM weights and trims, exact PANTONE TCX colourway specifications, and size-grading measurement sheets. Without a precise tech pack, factories cannot manufacture kits accurately, leading to costly production errors.