Download IGT Pick & Blister (PDF)

This test measures the ability of coated or uncoated paper or paperboard to resist picking or blistering during offset printing. The test device operates by applying a know film thickness of polybutyne oil, which has a known viscosity, to the sample surface while under acceleration, ie, the applicator speed increases from 0 m/s to 4 m/s during the application. The oil creates a pulling action on the paper surface, like offset ink, resulting in picking, blistering, or both. The point at which the picking and blistering starts is the end point of the test. The reported units for both pick and blister area viscosity-velocity product (vvp). At a known oil viscosity, this indicates the velocity or press speed that can be achieved before the sheet is damaged.

This instrument can be used for many print and surface quality tests, in addition to pick & blister testing. It has two print stations for applying ink and coatings. Various combinations of ink applications are possible. Other tests such as back trop and water interference mottle evaluation can be investigated. The instrument can also be used to measure diverse paper surface properties. Like water and oil absorption or surface roughness.