In sewing and fashion design, a pattern is a template from which the parts of a garment are traced onto fabric before being cut out and assembled. Patterns are usually made of paper and are sometimes made of sturdier materials like paperboard or cardboard if they need to be more robust to withstand repeated use. The process of making or cutting patterns is sometimes condensed to the one-word Patternmaking, but it can also be written pattern(-)making or pattern cutting.
A sloper pattern (home sewing) or block pattern (industrial production) is a custom-fitted, basic pattern from which patterns for many different styles can be developed. The process of changing the size of a finished pattern is called grading.
Several companies, like Butterick and Simplicity, specialize in selling pre-graded patterns directly to consumers who will sew the patterns at home. Commercial clothing manufacturers make their own patterns in-house as part of their design and production process, usually employing at least one specialized patternmaker. In bespoke clothing, slopers and patterns must be developed for each client, while for commercial production, patterns will be made to fit several standard body sizes.
A patternmaker typically employs one of two methods to create a pattern.
The flat-pattern method is where the entire pattern is drafted on a flat surface from measurements, using rulers, curves, and straight-edges. A pattern maker would also use various tools such as a notcher, drill, and awl to mark the pattern. Usually, flat patterning begins with the creation of a sloper or block pattern, a simple, fitted garment made to the wearer's measurements. For women, this will usually be a jewel-neck bodice and narrow skirt, and for men an upper sloper and a pants sloper. The final sloper pattern is usually made of cardboard or paperboard, without seam allowances or style details (thicker paper or cardboard allows repeated tracing and pattern development from the original sloper). Once the shape of the sloper has been refined by making a series of mock-up garments called toiles (UK) or muslins (US), the final sloper can be used in turn to create patterns for many styles of garments with varying necklines, sleeves, dart placements, and so on. The flat pattern drafting method is the most commonly used method in menswear; menswear rarely involves draping. You can learn pattern drafting on many fashion design courses either on a short further education course or as part of a Fashion degree at a university.
The draping method involves creating a muslin mock-up pattern by pinning fabric directly on a form, then transferring the muslin outline and markings onto a paper pattern or using the muslin as the pattern itself. Designers drafting an evening gown or a sculpted dress that uses a lot of fabric typically cut on the bias will use the draping technique, as it is very difficult to produce with a flat pattern.
After a paper/fabric pattern is completed, very often pattern-makers digitize their patterns for archiving and vendor communication purposes. The previous standard for digitizing was the digitizing tablet. Nowadays, automatic options such as scanner and camera systems are available.
Mass market patterns are made standardized, while human bodies vary, so store-bought patterns only fit a small proportion of people well, and an experienced sewist can adjust standard patterns to better fit any body shape.
So, a sewist may choose a standard size (usually from the wearer's bust measurement) that has been pre-graded on a purchased pattern. They may decide to tailor or adjust a pattern to improve the fit or style for the garment wearer, using french curves, hip curves, and cutting or folding on straight edges. There are alternate methods, either directly on flat pattern pieces from measurements, using a pre-draped personalized sloper or using draping methods on a dress form with inexpensive fabrics like muslin.
Creating a muslin (also called toile using calico), similar to a garment template, is one method of fitting. Muslin material is inexpensive and is easy to work with when making quick adjustments by pinning the fabric around the wearer or a dress form. The sewist cuts muslin pieces using the same method that they will use for the actual garment, according to a pattern. The muslin pieces are then fit together and darts and other adjustments are made. This provides the sewer with measurements to use as a guideline for marking the pattern pieces and cutting the fabric for the finished garment.
Pattern grading is the process of shrinking or enlarging a finished pattern to accommodate it to people of different sizes. Grading rules determine how patterns increase or decrease to create different sizes. Fabric type also influences pattern grading standards. The cost of pattern grading is incomplete without considering marker making.