For telemark and randonee skis with wide tips and tails, you have 2 choices. You can use waist-width skins on these skis, but a significant portion of the ski base at the tips and tails will not be covered, reducing climbing grip. Or you can buy skins in a width close to that of your skis' tips and then trim them to the exact hourglass shape of your skis, allowing optimal climbing grip.