Pellon Fuse-N-Shape Mediumweight Fabric Interfacing White. 15 x 36 Precut Package. Add firm support to your fabric projects with Pellon Fuse-N-Shape Medium Weight Fusible Interfacing. This innovative polyester product is resistant to distortion. It s fusible on both sides of the material making it ideal for picture frames place mats fabric bowls window treatment accents lamp shades and more. Simply tuck a protective layer between the ironing board and interfacing. Press your iron down and use a crosswise motion to apply heat. After your fabric is firmly fused to the medium weight interfacing trace a design and cut it out.