The One Basil: One-Piece Fit and Care Guide
By Form and Fold | Published: 2026-10-22
Category: Buying Guides
Learn how The One Basil one-piece fits D+ busts, how to choose your size, and how to care for recycled sculpting fabric to keep it looking great.
Quick Answer
The One Basil is a sculpting one-piece with a hidden underwire bra designed for D+ busts, so choose your usual bra size for the top and your usual bottom size, then hand-wash in cold water to protect the recycled fabric.
Why the built-in bra changes your size choice
Unlike many swimsuits that rely on removable cups or shelf bras, The One Basil has a hidden in-built underwire bra. That means the top half is sized like a bra, not like a generic S/M/L. If you are a D cup or larger, the underwire provides real support, but it also means you should pay attention to your band and cup size rather than just your dress size.
The scooped low back and adjustable straps give you some flexibility, but the underwire still needs to sit flat against your ribcage. If the wire digs in or the cups gap, the size is off even if the rest of the suit feels snug.
What the recycled fabric means for care
The One Basil is made from recycled sculpting fabric, which behaves a bit differently from standard nylon blends. It is designed to hold its shape and provide compression, but that also makes it more sensitive to heat and harsh detergents. Chlorine, salt water, and sunscreen can break down the fibers over time, so rinsing after every wear is not optional.
Because the suit is fully lined with a second skin lining and has bagged-out seams for a flat finish, it is less likely to show lines under clothing. But that lining also means the suit takes longer to dry, so avoid wringing it out or tossing it in the dryer.
The One Basil: Your Top Questions Answered
- How should The One Basil fit?
- The suit should feel snug but not painful. The underwire should sit flat against your ribcage, and the cups should fully contain your bust without gaping or spillage. The bottom should have medium coverage, so it should not ride up when you move. If the underwire lifts away from your chest, go up a band size.
- What size should I order?
- Use your bra size for the top and your usual bottom size. Because the suit is one piece, check the brand's size chart to see how those two measurements map to a single size. If you are between sizes, size up for comfort, especially if you are a D+ cup. Measure your underbust and bust before ordering, and compare them to the chart.
- How do I wash The One Basil?
- Rinse it in cold water immediately after swimming to remove chlorine, salt, and sunscreen. Hand-wash with a mild detergent, then lay it flat to dry away from direct sunlight. Do not wring, twist, or machine wash. Never put this suit in the dryer; heat will break down the recycled elastic.
- Can I wear The One Basil for swimming laps?
- Yes, the sculpting fabric and underwire bra keep everything in place, and the medium bottom coverage stays put. Just be aware that chlorine can fade the color over time, so rinse thoroughly after each swim. For frequent pool use, consider rotating between two suits to extend the life of each.
- How should I store it?
- Fold it loosely and store it flat in a drawer, away from direct sunlight and heat. Do not hang it by the straps, as that can stretch them out. Keeping it flat preserves the shape of the underwire and the fabric.
About The One Basil
- The One Basil: Hidden in-built underwire bra with adjustable straps and a scooped low back. You get real bra support in a one-piece, so you can size by your bra measurements instead of guessing with generic swim sizes.
The One Basil - The One Basil: Recycled sculpting fabric with seamless construction and bagged-out seams for a flat finish. The fabric smooths and shapes like shape wear, but it needs gentle, cold-water care to keep its compression and avoid pilling.
