Identified as shirring. However, the look it generates is similar to smocking, that's an embroidery procedure that’s existed a lengthy while. But perhaps don’t google “precisely what is smocking” cuz seemingly it also refers to a thing that has practically nothing to try and do with sewing… In any case, https://covered-spandex-yarn21975.bloginwi.com/65592302/rubber-covered-yarn-for-dummies