I had to struggle to get my thread through the gimp - I mean it took me several pieces of gimp and lots of pulling. As it was my first attempt I found my thread size in relation to hole/gimp size was not ideal. I think you can use a smaller piece of gimp, leaving a smaller amount exposed. My pieces were less than and 1/4 inch. The clasp is snug.
Here is the link to the photos of my first attempt - it is by no means perfect, but I'm happy for now. I'm sure the others will have lots to add; helping us both.
http://picasaweb.google.com/lisamla/...ey=YOxrzdQp29w