Term for any of a variety of tests used to determine the likelihood that a particular ink and substrate combination will result in blocking when printed. The factors that contribute to blocking—pressure, drying time, temperature, humidity—are varied and inflicted upon a press proof containing the ink and substrate to be printed. Block tests vary from simple "finger twist" tests, in which a press proof is twisted tightly and examined for setoff and ink film breakage, to elaborate tests utilizing ovens that vary the pressure, temperature and humidity to which the sample is exposed. Also known as Blocking Tests.
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