Schematic of relationships among paper properties of unit width compression strength Su, unit width extensional stiffness EAu, unit width flexural stiffness EIu, effective thickness te, and caliper tc in machine direction, MD and cross machine direction, CD. Solid lines represent theoretical relationships according to equations 1-3. Broken lines represent correlations according to equations 4-6.
| 1 | te2 = 12 EIu / EAu | 4 | te = a + b tc |
| 2 | te MD = te CD | 5 | Su CD = c (EAu CD)1-d |
| 3 | EAu MD/ EAu CD = (Su MD/ Su CD)2 | 6 | EAu MD = e EAu CD |
Given any combination of one through six of the properties show shaded, all remaining properties can be determined by invoking the assumptions ranked above in order of increasing severity.