Warp Knitting: Runner Lengths to Fabric Weight & Machine Output

Runner is per needle, not per bar across the bed, and that is the single most common misreading of the figure: a bar does not feed 1250 mm, it feeds 1250 mm to each of the needles it laps. The bed count comes from gauge times working width, so a partial threading or a bar that laps only part of the width will overstate consumption here in proportion to the part not threaded. Bar share is reported because GSM cannot distinguish a short ground against a long inlay from two bars sharing the work, and those two fabrics behave differently under tension however alike they weigh. Course density is measured, not derived: it is the input the whole area calculation rests on, and taking it from a specification rather than from the cloth is how a weight calculation comes out confidently wrong. Yarn consumption per hour is yarn fed, which is not yarn bought - it excludes creel waste, the ends lost at a beam change and anything a stop mark costs. Elastane on a bar is quoted in dtex like anything else here, but it is fed under draft, and a runner measured on the machine already includes that draft while a figure taken from a recipe may not.