Pin Adhesion is a test of corrugated board. It measures the strength of the adhesion of the flutes to the adjacent liner. Testing is run according to TAPPI Test Method T821. There are a couple of different ways to run the test. There is a selective method, in which the operator forces failure to occur on only one side, measuring the force required to separate the flutes from the liner. There is also a non-selective method in which the failure is allowed to occur at the weakest interface.