A one-piece has to fit shoulder, torso, waist and hip at once. Before buying, compare body and garment measurements instead of assuming your usual dress size will translate.
Torso length changes everything
Ask for shoulder-to-crotch length measured along the front and back, as well as bust, waist and hip. Adjustable straps add some tolerance; a fixed fitted bodice adds very little. For strapless pieces, confirm that internal support is intact.
Check every closure
Long invisible zips are placed under more tension in a jumpsuit than in a loose dress. Request close photos of the base, teeth and pull. If a style uses hooks, press studs or ties, make sure every component remains attached.
Allow for movement
Rise and thigh ease affect sitting and bending. A seller’s standing photo cannot show this, so flat measurements are essential. On short playsuits, total length and leg opening help predict coverage.
Examine seam intersections at the waist and crotch. Small loose threads can be repaired; puckering or pale stress lines may mean the fabric itself has weakened.