How do you decide when to stop the stretch? As we are going along, we test the skin with a bachi beat in the center, carefully listening for the pitch going up. We also look at the mimi to see if there are stretch or stress marks indicating trouble. We have been told from expert drum makers that the skin should be stretched as much as you dare to. The drum will be very high pitched and tin can sounding at first, but it will last the longest and sound great even at first when heard by the audience.