Now and then, I get paid to make someone look fat. Contrary to what a few actresses may claim, that is not normally my goal, but about once a year I make some sort of padding for a show. Earlier this year I built a Pan costume with padded out haunches, and last year I got to pad men to look like corseted Victorian women for The Mystery of Irma Vep. This time around we're doing a Christmas show by A. R. Gurny called Indian Blood. One actress plays 3 of the minor characters, one of whom is described as "a Polish woman of ample proportion." The play is set in the 1940's, so I set out with the intention of creating a different and larger body for her that would give the impression of a large woman wearing a fairly firm foundation garment.
The right side of the photo will give you some sense of the size and shape of the actress before padding.
I started with a muslin base fitted to the actress, and then built onto it with filter foam (used in AC, air purification systems, etc). Because the filter foam is very open, it will dry quickly after washing.
I try to form padding in sections, partially to best mimic how flesh sits on the body, and partially to allow the padding to move with the wearer's body--so that they don't just look like they've stuffed pillows down their shirt!
I covered the padding with another layer of muslin, so it's a simple unit, easy to clean and wear, with a zipper up the back. In most cases I would make this cover in spandex to be smooth and skin-like, but in this case I wanted a firm woven cover to mimic a hearty undergarment. We did add spandex sleeves with a little padding to add just a little waddle to her otherwise too thin arm.
Finally I draped the actually costume over the padding. They are two pieces for the sake of laundry, but go on as one for the sake of the dresser. The actress, by the way, was thrilled to wear it! So gratifying for us, as some actresses have been made so insecure by years of auditions and agents that they might refuse to go on stage in a fat pad, or insist that the program note that they are padded and not actually fat. Hooray for the secure actresses!