The basics Jumbo Wonder Clips have great holding capacity for many crafts. The benefits Clip opens wide to hold layers of fabrics. The uses Jumbo wonder Clips are a great alternative to pins, especially when working with vinyls, piles, and heavy weight fabrics. Also perfect for hanging patterns to view and organizing quilt block pieces! The bottom line The flat back of the Jumbo Wonder Clips have seam allowance marking for 1/4”in, 1/2”in, 3/4”in, and 1”in.