No knots needed. Atlas-Mikes Magic Thread makes spawn sac tying easier. Simple, fast, and effective just 3 wraps around the stem of the sac, a pull, 3 more wraps, and another pull does it. Magic Thread is also an excellent bait saver. Simply wrap it around your shrimp, herring, crayfish or minnow bait for a secure hold. 100 per spool. Color: Red. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Soft Baits.