Распределенные по размерам (S, M, L, XL, etc) коррективы, которые нужно вносить в выкройку для той или иной модели в зависимости от типа детали (рукав или горловина) и типа ткани: того, как ткань ведет себя в носке (степени усадки ткани или степени растягивания).


У каждой компании существуют свои правила градации (grading).

http://www.craftsy.com/article/pattern-grading
http://www.fashiondex.com/publications/designandproduction/s...
http://www.fashion-incubator.com/archive/what-are-grade-spec...

A grade specification is the measurement indicating how much each size should grow or shrink.

Grading of a pattern (or grading of size spec measurements) means adding or decreasing inches (or other measurement units such as millimeters), to a specific part of the sample sized pattern in order to size up or size down. In other words, when grading you are creating a size run of varying dimensions and sizes. For example, if your sample size is size medium, you will need to grade "up" to determine the measurements for size Large and X-large etc. If your sample is size medium, you will need to grade "down" to determine the measurements for size small.

In order to do this, you need to have established grade rules.

Unfortunately, grade rules vary from company to company. Also, they change depending on the fabrication. For example, the grade rule for the neck opening for a knit top may be different for the neck opening for a woven top. It is important to take into account that knit will stretch more then woven and therefore, may require different rules.

For example, one company may grade the sample size's waist measurement up 1 1/2" to make a size six a size eight. However, another company may grade the sample size's waist measurement up 1 1/4" to make a size six a size eight. Because their is no apparel industry standardization each manufacturer or designer has the opportunity to decide how their production pattern gets graded. They determine their standard sample measurement as well as their specific grade rules.