How a tie side bikini works
The bottom is held in place by two ties, one at each hip. You knot them yourself, which means the fit is personal to your body rather than fixed at manufacture. Most tie side bottoms use long fabric or string ties that can be knotted at different heights: tighter and higher creates a more elevated leg line, lower and looser gives more coverage and a more relaxed silhouette.
Because sizing is adjustable, tie side bottoms tend to work across a wider range of body shapes than fixed-waist styles. The knot sits at the widest point of the hip, framing rather than cutting across it. The high-cut leg that most tie side styles create draws the eye down and along the leg, making the leg appear longer.
Coverage depends on the cut of the fabric itself, not just the tie position. Tie side bottoms come in everything from minimal to full coverage. The tie determines where the piece sits; the cut determines how much it covers.