Last modified on Wed 31 Mar 2021 13.27 EDT Only a few swimsuits have ever made it into the Costume Institute collection of the Metropolitan Museum in New York and the best known is perhaps the least substantial, a super-simple shape sewn from a scarce metre of white nylon fishnet. It has a tactfully lined crotch but the mesh does not conceal breasts and nipples, yet it is not crude or sleazy. On the perfect body, it would be witty. The perfect body concerned belonged to Cheryl Tiegs, the leading model in 1978, when Monika Tilley was asked to design the garment specially for Sports Illustrated magazine’s annual pin-up fest, its swimsuit issue.