She says it better than I could!
http://www.nytimes.com/2010/07/08/nyregion/08experience.html?_r=1&ref=nyregion
"Engineering and architecture: A costume is not clothing. It is not fashion. It is couture, but not the kind of couture where one person wears an outfit three times. It’s a combination of soft engineering and soft architecture. We take a pattern from the designer and build the costume with the expectation that it will last 25 to 30 years and withstand multiple alterations. This season we fitted and altered roughly 2,000 existing costumes. For the new production of “Carmen” alone, we built 550 costumes."
Yup, that sounds like my job, all right. Don't ever think this job is easy just because I do what I love every day!