“DTF lines and small details should be at least 0.5 mm thick to hold adhesive powder and bond”

t-shirt.ca gives 0.5 mm as the minimum for DTF lines and small details, and says very thin lines may not collect enough adhesive powder to bond. The figure is one shop's rule and the mechanism is stated as a possibility, not measured. Printful sets its line minimum at 1 pt in Illustrator, about 4 px at 300 DPI or roughly 0.35 mm, so 0.5 mm sits at the strict end of what shops ask. As a safe design rule it holds; as the threshold below which DTF fails, it is not established.