All material tested has been in a constant laboratory environment of 21°C and 65% humidity level for a period of minimum 24 hours prior to testing.

In the collection of data Suessen has used one Zweigle Hairiness Tester Model G 566 with cop changer. Zweigle has used 4 models G 566 and 1 model G 567.
 

All of the above mentioned machines have been outfitted with OPTO-CHECK, and a calibration check conducted on a weekly basis.