After opening the can, you should use the balls within 2 months. Depressurised balls lose their bounce after two months without use.
Before being taken out on the court, our balls undergo several tests. Lab tests check elements like the quality of its bounce, hardness, sizing, etc... Field tests are conducted with our partnered testers to evaluate the performance of our products in real game conditions. These balls are approved by the ITF (International Tennis Federation), the FFT (French Tennis Federation), and the FIT (Italian Tennis Federation).
Steve Darcis (ATP singles No.2 on 22/05/2017), Oliver Marach (ATP doubles No.2 on 01/11/2018), Nicolas Escude (former ATP No.17), all Artengo technical partners, and many other high-level players.