The rubbing test, ISO 105-X12, rubs a piece of white cotton against the fabric, dry and then wet, and grades how much dye was transferred. Typical grades asked for clothing are 4 for dry and 3 or 3-4 for wet; dark colours can fall to 2-3 wet and stay acceptable only if the brand allows it. It matters most for black, red, intense colours and for white garments worn next to them.
Ask for both dry and wet grades and put them in the order. If a shade marks skin or a white shirt, the problem shows up straight away with the end customer.
rubbing-fastnesscrockingiso-105-x12
