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Apparel patterns capturing the input of a designer
Apparel patternmakers draft patterns based on a designer's sketch of a style. The designer gives the sketch to the patternmaker, who can ask questions to determine details the designer is looking for.
Patterns may be drafted on paper or in a computer program designed for patternmaking. Most of the time, in modern American samplerooms, the patternmaker pulls an existing pattern (or block) and makes a modified copy of it to match the new style, either on paper or on computer. If it's a completely new style, the patternmaker will usually drape a rough draft in muslin fabric on a dress form, then show it to the designer to discuss any changes before transferring the markings to paper to create the pattern for cutting. Patterns may also be drafted from measurements, but this method has fallen out of use, as it's less accurate and takes longer than the other methods. Patternmakers are also asked to copy existing garments without damaging them. This is a common practice in American samplerooms.
Patternmakers have a combination of engineering and design skill. They need to be able to understand what the designer wants, and translate that into the lines of a pattern that will cause the garment to fit correctly. Ideally the pattern captures not only the fit, but also the flair intended by the designer.
Patternmaking is taught in conjunction with fashion design education, as it is vital for designers to understand the apparel development process. It is also taught as a major at certain trade schools. There are many books on the subject, but it is rare for a patternmaker to become a professional through teaching oneself. Apprenticeships are almost unheard of in modern America, but would serve well to improve the transition from student to professional status. Because this occupation is relatively unknown outside of the apparel industry, there is a serious lack of patternmakers who can accurately interpret designs in Los Angeles, and possibly other fashion capitals.
Metal casting patterns used in foundries
Foundry patternmakers have historically been woodworkers with skills of a woodcarver, woodturner, and cabinet maker. When an object is made from cast iron, cast aluminum or any liquified metal the patternmaker is employed to make a wood model of the object. The original pattern has to be made slightly larger as metal shrinks when it cools and often the pattern made in puzzle like parts as the sand mold must be "rammed up" in a certain manner and the parts of the pattern must be removed from the sand mold without altering the negative space which is left behind in the sand. Pattern makers also have evolved into cutting negative spaces into blocks of steel where sheet metal will be pressed between two matching shapes. A dinner fork is a good example. A block of steel is made to mirror the back of the fork and a block of steel is made to mirror the top of the fork.