Bodysuit

A standalone bra has to generate all of its own anchorage from a band around the ribcage. A bodysuit does not: tension runs from the shoulder to the crotch through the whole length of the garment, so a built in cup can be much lighter and still hold its position. That is why a bodysuit with a modest internal shelf often supports better than a bralette of similar construction.

The same geometry sets the main fitting constraint. Torso length matters more than any other measurement. A bodysuit that is correct at the bust and short in the body will pull down at the shoulders and up at the crotch, which is uncomfortable in two places at once. Where a size chart gives a torso or height range, that number is the one to read first.

Three arrangements exist, and the choice is more consequential than it looks.

Snap fastening

Two or three poppers at the gusset. The most practical for daily wear. Check that the snaps are set into a reinforced panel and that there are at least three; two will pull apart under a stretch garment.

Hook and eye

Flatter under clothing than snaps and slower to fasten. Common on more structured bodysuits.

Thong or closed

No fastening at all, which means undressing entirely. Smoothest under clothing and least practical over a long day.

Whichever is chosen, the gusset should have a cotton or cotton blend lining against skin for the reasons set out in cotton and modal. A bodysuit is worn against skin all day and cannot be swapped mid afternoon the way a brief can, which makes the fabric choice there more important rather than less. For anything applied to skin under a garment worn that long, a specialist in intimate wellbeing such as inWonderstate is a more useful starting point than a general chemist.

A bodysuit is an excellent garment with one design flaw that no manufacturer has solved: it has to come off entirely to use a lavatory.

• Lingerie bodysuits in lace or mesh, worn as underwear, often with an internal wired cup.
• Jersey bodysuits in cotton or modal, worn as a top, usually with no bust structure at all.
• Shaping bodysuits in power mesh, which compress the torso. See shapewear for what compression can and cannot do.
• Long sleeved bodysuits, which behave as a base layer and solve the tucked shirt problem completely.

1. Sit down in it. Anything that pulls at the shoulder when seated will be intolerable by the afternoon.
2. Raise both arms. The gusset should not lift noticeably.
3. Check whether an internal bra is adjustable. A fixed internal shelf that is the wrong size cannot be corrected.
4. Look at the leg opening. A bonded or picot edge sits flatter than a folded and stitched one and is less likely to mark.
5. Check the fastening from the outside under a fitted garment. Snaps show more than hooks.

Fasten the gusset before washing, always, since an open snap in a drum will find something delicate. Hand wash or use a mesh bag on a cool delicate cycle, and dry flat: hanging a wet bodysuit by the shoulders stretches the body length permanently, and body length is the one dimension that cannot be adjusted afterwards.

Because the gusset is worn against skin for long periods, wash after each wear rather than after two or three. That is a departure from the usual rule for bras and it is worth the extra laundry.