Warp Knitting
The runner ratio between the bars is the fabric. Change it and you have a different cloth at the same weight, gauge and yarn.
— g/m²
Both guide bars together, loom-state
Loom-state weight before relaxation and heat setting. A ratio far from the machine builder's window for the lapping usually shows up as barré or curling long before it shows up in the weight.
Warp Knit Rack Length & Two-Bar Run-in Ratio Calculator — free, with the formula and a worked example, at Textile School.