Keith Johnson, KJ Bubbleguy, originally conceived of and open-sourced the now popular bubble garland some time ago. This is my 18 loop updated anti-fold-over design using 3/16" diamond-braid SecureLine clothesline cord by Lehigh with a removable core. It can be found here. It can also often be found at WalMart. The Walmart version (label circa 2013) is shown on the Wicks page. This cord type is recommended by Glowby the Bubbler and has proven to be very productive--thanks to both of you
PREPARING THE CORD: I recommend that you prepare/condition the new cord to remove the "newness" from the material; either by washing in bleach or soaking in white vinegar overnight. It is also important to abrade the new cord thoroughly to break down the stiffness. See Glowby's article On the Treatment of Diamond Braid Cord.