What to do to prevent the paint from sagging?

Paint should be applied in suitable weather conditions and the ambient temperature should be between +5 and +35 C.  It is the downward "drooping" movement of the paint film immediately after application. This problem is usually faced with synthetic based paints. The reason for this problem to occur is the failure to use a proper brush/roller, overthinning the paint and application of a heavy coat of paint on the surface. To solve this problem caused by incorrect application, the painted surface should be sanded after the paint has completely dried and be repainted in accordance with the legend information provided.