Based on the accomplished measurements, several porosity parameters were calculated according to equations 1, 4, 8 and 9 presented in the Introduction. They are shown together with air permeability measurements in Table 2. The last row of the table shows values of the coefficient of determination (R2) between the air permeability and the corresponding physical and porosity parameter. High R2 values indicate that each of the six calculated parameters has a strong influence on air permeability of fabrics.