Video: Slipknot (Buttonhole/Jeny’s Stretchy Slipknot) Cast-On
The Slipknot Cast-On is a reversible and very elastic short-tail cast-on that can be used to add stitches to stockinette or ribbing.
This cast-on is simply a series of slipknots done with the working yarn.
The key to success for this cast-on is to keep all the slipknot stitches very close together, and pull each stitch tightly to secure it. The cast-on is so elastic that you can't afford to leave any slack in the yarn.