In chemistry, a polymer is "polydisperse" when its chains aren't all the same length, but instead follow a distribution of sizes. Applied to bubbles, this means combining two or more different thickeners — for example guar gum with PEO — instead of relying on just one.
Why does it work?
A study from Emory University (Frazier, Jiang & Burton, 2020) found that a blend of polymers with varying chain lengths produces a film that stretches better and holds up longer than the sum of its parts. The long chains provide extensional strength; the short ones fill gaps and add stability. The result: more elasticity with a lower total polymer concentration, which also saves on materials and keeps the mix from turning sticky.
That's why many record-setting recipes don't rely on one star ingredient, but on a well-calibrated combination. In the KUANTIKA simulator, the engine explicitly rewards polydispersity when scoring formulas for giant bubbles.