A test to determine a paper's resistance to water on its surface, or the adequacy of its sizing, in which a drop of water is placed on the paper's surface and after a set period of time the angle between the paper's surface and a line drawn tangent to the surface of the drop at the point where it contacts the paper's surface. If the angle is close to 0º, the drop will have been almost totally absorbed into the paper. The greater the angle, the less wetting will have occurred. If the angle is beyond 90º, the drop will have simply remained beaded on the paper's surface.
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