Patternmakers, also called patterncutters, are responsible for making the "blueprints" of the apparel items. For each style, there will be a size (usually in the middle of the range of sizes) that all the other patterns for that style will be based off of. In order to change it from one size to another, there must be pattern grading. Pattern grading is when, at certain points, the pattern is taken in or let out. These changes will affect how much the waist, for instance, will become larger when it goes from a size 12 to a size 14. Since there are no laws regulating differences from one size to another, these changes will vary from one organization to the next. What is a size 10 may be a size 6 in another company. To further complicate matters, different countries use different numbers to represent the same size.
For each size within a company, a basic pattern block will be used. This basic pattern block represents the minimum ease necessary in order to produce a basic garment. Ease is the difference between what the fabric measures at a given point and what the actual fit model's measurement is. Minimum ease is the amount of ease that must be present in order for the garment to fit properly. Without this ease, there will be problems such as discomfort, seam rupture, and many others. All other patterns will be based off of the basic pattern block. From this, adjustments will be made according to the creative and technical design teams' descriptions in order to produce a given style.
Although most patterns were once done by hand, most patterns today are done on the computer. The patterns are then printed, a sample garment is made, fit is checked, and any necessary adjustments are made accordingly.