Grading Rules Explained

A grade rule states how much a specific measurement point — chest width, sleeve length, armhole depth — grows or shrinks per size step, moving out from a base size. Applying grade rules across every point on a pattern produces the full pattern set for every size in the run.

Linear grading applies the same increment at every size step. Non-linear grading changes the increment as sizes get larger or smaller — for example, growing chest width more per step in the largest sizes while growing sleeve length less, matching how body proportions actually shift across a size range rather than scaling everything at one constant rate.

• Preview the smallest and largest sizes first — a bad rule usually shows up at the extremes before it shows up near the base size.
• Check that grain and proportion still look correct on non-base sizes, not just the measurement numbers.
• Re-run simulation on at least one extreme size fabric-and-fit check before finalizing a size chart.