Grading is the process of creating a range of sizes from a single sample size in a garment design. Grading is also commonly called sizing or multi-sizing a pattern, making it larger and smaller to fit the body sizes the design is intended for in the same way that the sample size does, with all the same design elements and style. It is a skill that requires the knowledge of garment construction, design, and fit, as well as the necessary technical skills specific to the area of garment production (ready-to-wear, sewing patterns, knitting/crochet patterns).

When does grading happen?

Grading comes after all design decisions have been made, most importantly after a test garment or sample is finished and the fit and design eases are confirmed. Depending on how the garment will be produced, the pattern for that one size may also be written or drawn out before the grading process begins.

How is grading done?

Here is where the process gets its name: grading is accomplished by using grade rules. These are measurements applied at specific points of the pattern to increase or decrease the total size by a particular measurement, which is also called a grade.

Grading in flat pattern

In garment manufacturing and in the sewing industry, pattern graders apply grades and size specifications to each flat pattern piece systematically to produce all the sizes required. Grading is often done using specialized computer software, but it can be done manually using rulers and other tools to cut and spread or shift the base pattern to produce the sizes. Each size has its own set of pattern pieces that are then used to cut out the fabric and construct or manufacture the garment.

Grading for flat pattern does not change the shape of the base design, but only increases or decreases the size. This means that there often needs to be more than one sample made to accommodate the changing body shapes as the sizes increase or decrease.

Grading for knitting and crochet patterns

In garments that are made with yarn, the fabric is produced at the same time as the garment pieces, so there are no physical pattern pieces used in the garment production. Instead, the grader (which can be the designer or a technical editor) uses spreadsheet calculations to apply the grade rules to the sample pattern measurements. They then write the pattern instructions that will reproduce the design for the various body sizes, including a schematic drawing and/or table that illustrates the finished measurements (and sometimes more instructions).

Grading for designs made with yarn is more flexible than in flat pattern because the grader is working with numbers and calculations, not physical patterns. Thus, there is rarely a need to make multiple samples and the shape of the garment can be easily adjusted so the finished pattern fits all the sizes well. 

Want to know if your knitting or crochet design is ready for grading? Read more here.

What grading is not

Grading is not adding or subtracting the same amount of design ease at every part of the pattern, nor applying the same percentage change everywhere.

As body sizes increase and decrease, the various body parts do not increase/decrease at the same rate. For example, if a chest circumference increases from one size to the next by 2”/5 cm, the neck circumference may only increase by ⅛”/0.3 cm. So adding the same 4”/10 cm of design ease at both the chest and neck as the sizes increase would yield a catastrophically ill-fitting garment.

What is a “good grade”?

• A well-graded pattern results in the same fit for all the body sizes. In each size, the neckline is proportional to the neck, the cuffs and hem all end at the same point on the body, and fit in the arms, chest, and hips are all the same. 

• A well-graded pattern also takes every design detail and scales it correctly to the body size: trims, pockets, cuff depths all will match the sample size in style.

• A well-graded pattern is inclusive in its size range. It is available for all body sizes in the market that the pattern is being sold to; no body size is excluded.

Want to learn how to grade knitting and crochet patterns?

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Sarah Walworth is a 1:1 grading coach and group instructor, as well as the owner of the Tech Editor Hub. She is a tech editor, knitting instructor, and loves to solve grading problems. You can find out more about her at www.sarahwalworth.com.