Grading is how multiple garment sizes are made from a single sample size. By consistently applying “growth” or “shrinkage” amounts at various places in the pieces of the garment, the pieces are changed uniformly. How these amounts of “growth” or “shrinkage” are applied, and the resulting pattern pieces are based on brand decisions.
Doing the same thing consistently on all pieces within a brand creates brand consistency with a size and between sizes. Brand consistency allows the customer to understand the brand’s sizing. Grading is applying a strict set of numbers between each size to accomplish a consistent product within each size. We are accustomed to sizes being fluid between brands (one brand’s size 2 is another brand’s size 00 or size 4!) but within a brand customer’s prefer consistency.
Grading is straight-forward in theory, but it can be tricky to do it effectively. This is made even trickier in knitwear due to stitch pattern, gauge variations, lack of a flat pattern, and the alpha method of sizing. Grading numbers are based on standards and a set of numbers that are developed and then used consistently.
Goals of Grading
- Make multiple sizes based on a single size;
- Be consistent in amount of change between sizes;
- Ensure that pieces will fit together in each size;
- Maintain the design integrity of the original size in all other sizes;
- Communicate the goals of the brand in each size offered.
Common Grading Misconceptions
- There is consistent growth in every area;
- That body type is not taken into consideration;
- All brands must use the same numbers in the same manner;
- That there are absolute rules.
Grading knitwear is usually done using a schematic or technical flat drawing and a system of formulas rather than through flat pattern. Knitwear usually uses an alpha sizing scheme (i.e., XS to XL; 1x to 5X) which requires a slightly different growth structure than numeric sizing.