Depends on the machine brand. To determine which way to load the bobbin into the bobbin case you need to determine which way the slot is facing that the tread slides into prior to it slipping under the tension clip. Hold the bobbin case with the opening away from you with the slot facing up. If the slot on the bobbin case is facing to the left put the bobbin into the case with the thread spinning the bobbin counter clockwise. If the slot on the bobbin case faces to the right put the bobbin into the case with the thread spinning the bobbin clockwise.