Appendix A: Test – Outer cover material

The following table explains how to test specific outer cover material characteristics.

How to test outer cover material characteristics

Characteristic Test Required results
Electrostatic charge retention American Standards Testing Method (ASTM) D4470 Less than 2.0 kV
Ink absorbancy
  1. Use a spatula to apply a thick layer of K&N testing ink over a spot larger than the aperture of the reflectance photometer.
  2. Leave the ink on the paper for exactly 120 seconds. Apply enough ink so that the spot stays well wetted for the full 120 seconds.
  3. At 120 seconds, use a spatula to remove the excess ink.
  4. Wipe off the rest of the unabsorbed ink with a soft towel.
  5. Wait 24 hours.
  6. Adjust a diffuse reflectance photometer to read 100% using the Commission Internationale de l’Éclairage (C.I.E.) Y tri-stimulus filter, illuminant "C", and a sample of the front surface of the tested sample. Read the diffuse reflectance over the ink spot.
 Maximum reflectance: 90%
Luminescence Compare the sample with "Domtar Lynx Opaque Cover" or a similar card stock as we determine from time to time. Less than these cards
Opacity Technical Association of the Pulp and Paper Industry (TAPPI) - T425 80% or greater
Reflectance Technical Association of the Pulp and Paper Industry (TAPPI) - T452

Minimum area reflectance: 30%

Maximum area reflectance: 96%

Maximum variation: 5%
Smoothness Technical Association of the Pulp and Paper Industry (TAPPI) Useful Method - UM-518 Between 25 and 330 Sheffield Smoothness Units
Thickness - cards or items ready for mailing Technical Association of the Pulp and Paper Industry (TAPPI) - T411 Not less than 0.18 mm