And the second article does a great job of explaining the grading rules that have to change across a large assortment of sizes:
"Waldman and co-founder Polina Veksler self-developed a technique for constructing plus-sized clothing called micrograding. They recognised the weakness of the standard formula for grading towards bigger sizes, which they compare to making a photocopy of a photocopy. “After a while, the pattern becomes distorted (a pair of culottes in a size 4 becomes a pair of palazzo pants by the time you reach a US size 24), so we started grading between every size, and using fit models across our entire size range whenever developing a new garment.”
It works. “When you have 11 models (representing alpha sizing) standing shoulder to shoulder, you can see right away if a dress meant to stop at the knee does so on a size 4XS as well as a XL,” they say"
This is the care and control that is needed to create a good fit across ALL the sizes!