Hercules Size Test
To view this document, you may need Adobe Reader or Adobe Acrobat.
HST (Hercules Size Test)
This is a measure of the sizing of paper or paperboard. The test measures the time required for a Formic Acid ink to penetrate the product and the test is run according to TAPPI Test Method T530. Various Formic Acid concentrations are used, depending on the paper product being tested.