How to Couch Threads
When metal threads are couched, silk thread is usually used. This gives a thin, strong thread which will blend in with the metal. You will want to use a couple of strokes of beeswax to give added strength and prevent the thread from fraying. Take a look at the illustration. You will see the top view of couching. Lay the metal thread on the area in which you would like to place it. Important: you should leave 1 or 2 inches tail to begin and end. These will be taken to the back of the canvas after couching has taken place.
With a small knot at the end of your silk thread, come up at 1 and go over the metal thread and back down at 2. Again, come up at 3 and back down at 4. You will repeat this process until you reach the end of the metal thread. The second illustration shows the side view of your canvas. To secure, see How to Plunge.