TAPPI T459

This method, applicable to uncoated and coated papers, is designed to measure the surface strength of paper or its resistance to picking. It is not applicable to loosely felted papers such as blotters or roofing felts nor to some coated papers containing thermoplastic resins in the coating adhesive.

In this test, calibrated sealing waxes with increasing adhesive power are pulled from the surface of the specimens. The highest number of the wax in the series which does not disturb the surface of the paper is the numerical rating of the pick.

Many printing and converting operations require the surfaces of the paper to have sufficient z-direction strength to give satisfactory results. Since no absolute values are obtained with this method, test results should be correlated with actual performance of the material during the subsequent coating, converting, printing or packaging operation.