Twoz/OTZ Hiding Power Test Paper 3B model, the upper and lower ends are white, the middle area is black, the varnish type, the paint is not permeable, and the surface is smooth.
| Model | color | Dimensions (mm) | type | Quantity per box (sheets) | brand |
| 3B | Black in the middle and white at both ends | 194x289 (7-5/8x11-3/8 inches) | Concealed varnish | 250 | LEADER |
Blocking force jam: Measure the hiding force with an instrument
Permeable cardboard: Used to evaluate the consistency of color and gloss of a voided surface
Visual assessment of hiding power:
- Comparison/coating rate jam
- Black and white grid/coating rate cardboard
Brush cardboard is used for informal brushing
Dedicated test jams for sag and leveling tests.
Sealed refers to the fact that the cardboard part contains varnish and is not easy to penetrate
Unsealed means that the cardboard part does not contain non-overprint varnish and is permeable

3B