Micron grade (adhesive powder).

DTF adhesive powder is sold by the size band its grains fall in, quoted in microns, and that band sets how thick the melted adhesive layer ends up under the print. STS specifies its soft TPU powder at 60 to 140 µm with a melting point of 80 to 95 °C, and the grades either side of that trade the same pair of properties against each other: fine grains lay a thinner, softer film that holds small type and clean edges, coarse grains build a thicker layer that grips heavy or open-weave fabric and stiffens the hand while doing it. Shops buy powder on price and on whatever the shaker was last set up for, then run one grade against every job that crosses the floor. Too fine under a thick blank and the transfer looks perfect at the press and lifts in the first wash; too coarse under small type and the grains bridge the counters, the letters close up, and a gang sheet full of unrelated orders reprints together. Grade is not a free swap either, because a shaker calibrated for one band puts down a different weight of the next one.