The salient features of a study of the dynamic wetting behaviour of several polyester tapes are given, together with the complementary fluid and air entrainment phenomena. Analysis of the data shows that there is no significant difference between data from different tape surfaces and that a correlation between Weber and Reynolds number adequately describes the results. A practical empirical formula (r > 0.99) is given which relates the air entrainment velocity to fluid properties. This has the form: This formula agrees with experimental data for fluids with viscosity in the range 0.004 < μ <0.5 Nsm−2 and surface tension in the range 0.025 < σ < 0.064 Jm−2 whilst predicting the air entrainment velocity to within 10% of experimentally determined value.