RUB RESISTANCE OF AN INK
The rub resistance of an ink corresponds to the greater or lesser tendency of the printed work to suffer from deterioration by rubbing with other unprinted stock of the same material and, besides the ink, it also depends on other factors, such as: the stock used and the printing conditions.
It is measured with an apparatus called Rub Tester, which has an arm with a weight (normally from one to two kg). The printed sample is placed below the weight and on another sample of the same stock, which is immovably fixed in place. The highest resistance corresponds to the highest number of cycles one sheet of stock can be passed over the other before any deterioration of the printed work occurs.