Here some close up shots of the details of my closure toggles. 

toggle_detail.jpg (5728 bytes) toggle_detail2.jpg (6462 bytes)
The toggles are simply small pieces of dowel that have had the edges smoothed and a small groove cut in the middle.  They are tied to one canvas loop and simply hook through the other. (Hopefully) you can see here the "box and X" stitching holding down each side of the loops.  Notice that the toggle is then tied to the canvas loop.  If a toggle breaks, I can always tie another on without having to un-sew/re-sew anything.


Another type of toggle is one that appears to have "cones" on either side of the string that ties it on, instead of being straight with rounded edges like mine.  The cross-section would look like this.