Patent ID: 7886590

Claim:
A method for determining the drying rate of a liquid film, comprising: (a) applying an amount of the liquid onto a first piece of a substrate to form an initial rollout proof having a head where the liquid is first applied to the substrate and at least one tail where the liquid is last applied to the substrate; (b) allowing the liquid to at least partially dry for a predetermined period of time; (c) repeating steps (a)-(b) to prepare at least one second rollout proof on a second piece of the substrate, said after rollout proof having a head where the liquid is first applied to the substrate and at least one tail where the liquid is last applied to the substrate, and allowing the second rollout to at least partially dry for the same predetermined period of time allowed to elapse in (b); (d) utilizing a densitometer to measure the density of each of the at least partially dried first and second rollout proofs, at the tails of the respective rollout proofs; (e) repeating steps (a)-(d) a plurality of times; (f) plotting the measured density of the tails of each of the respective rollout proofs versus a parameter related to the elapsed time at which the density measurement was made, to form a graph with at least one curve, which is representative of the drying rate of the liquid.