Turning corners
The method used to turn corners depends upon two things: the number of passing threads being used, and the angle being turned. Where there is only one passing thread a single angled stitch at the corner is sufficient provided the thread isn’t being turned 180? back upon itself. In that case, after turning the thread through 180? put a single stitch that goes over both threads. This prevents the thread from ‘spreading out’ at the corner and maintains the straight line of the thread.

If you are working with multiple threads then these can be turned gradually around a bend as shown. This leaves some of the fabric showing between the threads. In this case work each thread separately rather than trying to couch both threads with the same stitch.

Sharper corners require a different approach. Angles up to and including right angles can be done with diagonal stitches at the point of the corner. Each thread should be stitched down separately as the length of thread required by the inner thread is less than that of the outer thread. Once past the corner the couching stitches can once more pass over both threads.

Very sharp angles require that at least one of the passing threads be ended and a new thread started. This is because there is physically not enough space for a loop of the thread within the point of the angle. Here the outermost thread defines the angle, and threads within it should be finished off and restarted in an alternating pattern.