Tapes based on acicular iron particles give an outstanding recording performance compared to γ-Fe
2O
3and CrO
2tapes. Especially in the short wavelength region the signal to noise ratio is, respectively, 12 and 7 dB better, whereas the bias noise level is somewhat lower. The iron tapes have a high coercivity, between 80 and

A/m, and hence the required bias is about 9 dB higher than for γ-Fe
2O
3. The print through properties are excellent.