The magnetic shielding properties of YBa 2Cu 3O 7− x coatings, sprayed on silver cylinders with the continuous detonation spray (CDS) technique, have been investigated in weak magnetic fields. Extended films 40–80 μm thick showed flat-sided sharp-cornered hysteresis loops. Critical penetration field values, when scaled for thickness according to Bean's model were 1.6–3.7 mTmm -1 at 77.3 K and 21–35 mTmm -1 at 4.2 K. In the actual samples, J c was calculated to be 0.95−1.4×10 3 A cm -2 at 77.3 K and 10−12.5×10 3 A cm -2 at 4.2 K. Relaxation rates S = 11−23 ×10 -3 were measured for the flux creep at 77.3 K, and were found to be much lower at 4.2 K. The CDS technique allowed one to have precise control of the film thickness, a high coating productivity and a relatively low (∼ 1000°C) processing temperature.