Joybuy Insights

Choosing women's underwear and loungewear: a guide to fit, fabric and function

A pretty picture and buzzwords like 'seamless', 'breathable' or 'shaping' don't always tell the whole story. When it comes to women's underwear and loungewear, the fibres, sizing, seams and care instructions are what truly determine whether a product will be comfortable for everyday wear.

Here are three common pitfalls to avoid:

  1. Unclear sizing
    A size like XS, M or XL can vary between brands and styles. Without waist and hip measurements, it's difficult to make the right choice. Underwear that's too tight can dig in, while material that's too loose can shift around.

  2. Misleading marketing about materials and sustainability
    The term 'sustainable' can refer to a specific fibre, a recycled component, or simply the brand's positioning. That's why it's important to check the actual fabric composition. For example, a Calvin Klein product listing might mention beechwood fibres/modal, but the composition also states 82% recycled nylon and 18% elastane. This information should always be verified on the product label.

  3. A design that doesn't suit your outfit or the occasion
    A women's thong might be less visible under close-fitting clothes, but a high waist, wide band or certain fastening could be impractical. A lace bodysuit works well as a statement layer, whereas a seamless thong is designed to create a smooth silhouette under your clothes.

Which specifications should you check?

1. Size, waist and hips

Don't just look at the letter size. Compare your own measurements with the size chart for the specific product. For the Calvin Klein Thong TRN Beechwood Women XS, the product information for size XS lists a waist of 62–65 cm and hips of 88–90 cm.

This is especially important for a shapewear bodysuit. The product listing for Feelingirl advises choosing a size up if you're between two sizes. While this isn't a general rule for every style, it's a useful tip for this particular product. Also, pay attention to your torso length, especially for a women's bodysuit with a press-stud fastening.

2. Fabric composition and feel

For comfortable lingerie, softness, elasticity and moisture-wicking properties are key practical considerations. Elastane usually provides stretch, while nylon, polyester, modal or other fibres affect the feel of the fabric and how you care for it.

Check:

  • the percentage of elastane or spandex for freedom of movement;
  • whether the gusset and lining are made from a different fabric;
  • whether the claim 'breathable' is supported by the fabric composition or weave;
  • the official fibre names on the label, as required by European regulations for textile fibre names;
  • whether the fabric should be hand-washed or is machine-safe.

For instance, a Feelingirl seamless bodysuit is listed as 74% nylon and 26% spandex. Another Feelingirl model lists 77% nylon and 29% spandex; these percentages don't add up to 100%. Use such details as a guide, but always check the label or the most up-to-date specifications when you receive the product.

3. Seams, fastenings and level of support

A seamless thong has less visible lines, but that doesn't automatically mean it's comfortable for everyone. Check the leg openings, waistband and any reinforced areas.

When it comes to shaping lingerie, you need to distinguish between:

  • light support: designed to create a smoother silhouette;
  • firmer shaping: often tighter around the tummy and waist;
  • bust support: depends on the band, cups and construction.

Terms like 'tummy control' and 'waist cinching' describe the product's intended function. They are not medical claims. For a bodysuit, also look at the number of press-studs, the adjustable straps and how you plan to wear the garment under your outfit.

Our recommendations for every need

Best for: Budget-conscious beginners
Calvin Klein Thong TRN Beechwood Women XS

Calvin Klein Thong TRN Beechwood Women XS

Why it's a great match: A compact women's thong for everyday wear, from a well-known brand with a specific XS size chart for waist and hips.

How this product avoids the pitfalls

The listed waist and hip measurements help you avoid the guesswork of relying on letter sizes alone. Be sure to check the fabric composition on the label.

Key benefit & highlights

Stretch design, minimal seams and machine washable according to the product description. Do not tumble dry.

Best for: Shoppers seeking premium quality
Feelingirl Lace V Neck Full Thong Sexy Outwear Bodysuit for Women M3 Black

Feelingirl Lace V Neck Full Thong Sexy Outwear Bodysuit for Women M3 Black

Why it's a great match: For those who want to wear their lingerie as a visible layer, for example under a blazer or for a special occasion.

How this product avoids the pitfalls

The adjustable straps allow for a customised fit, while the V-neck and lace trim are clearly described rather than just being used as style terms.

Key benefit & highlights

87% nylon and 13% spandex for the outer layer; 11 press-studs at the gusset and hand-wash care instructions.

Best for: Specific uses & frequent wearers
Feelingirl Tummy Control Seamless Lightweight Thong Bodysuit

Feelingirl Tummy Control Seamless Lightweight Thong Bodysuit

Why it's a great match: For anyone looking for a shapewear bodysuit to wear as a base layer under office outfits, dresses or occasionwear.

How this product avoids the pitfalls

The seamless construction is designed to create a smooth silhouette. If you're between sizes, the product information advises choosing the larger size.

Key benefit & highlights

Tank-top style, non-compressive bust design and a press-stud fastening. Hand wash and dry flat.

Best for: Relaxing at home
Purcotton Women's AirySoft Gauze Loungewear Set

Purcotton Women's AirySoft Gauze Loungewear Set

Why it's a great match: A women's loungewear set for home, relaxed evenings and lazy mornings. The long trousers are perfect for those who prefer more coverage.

How this product avoids the pitfalls

The set is specified as a combination of a top and long trousers. Before buying, check the available body measurements and the current material information.

Key benefit & highlights

Long-trouser style and a design offered as a casual loungewear set. The product page includes size options; check the details before ordering.

Looking for more options?

We've put together a complete, up-to-date list of products that fully meet these strict selection criteria and comply with all applicable European safety regulations.

How to make your items last longer

The lifespan of your underwear and loungewear depends heavily on how you use and care for them. Always follow the instructions on the label, even if the online product description says something different.

  • Wash delicate lingerie in a laundry bag whenever possible.
  • Do not use bleach on elastic or lace fabrics.
  • Avoid the tumble dryer when it is explicitly advised against.
  • Allow shapewear and bodysuits to dry flat, gently reshaping them as they dry.
  • Rotate between several pieces to reduce stress on elastic bands.
  • After washing, check for loose seams, distortion or a stretched-out waistband.

For durable womenswear, it's not just about the fibre. A garment that fits well, is washed with care and worn regularly also prevents unnecessary replacement. However, the claim 'sustainable' remains brand or product information; always check the composition and care instructions for yourself.

Frequently Asked Questions about women's underwear and loungewear

How do I choose the right size for a women's thong?

Measure your waist and hips at the points indicated in the size chart. Compare these numbers with the specific model. For a bodysuit, you should also consider your torso length and the position of the press-stud fastening.

Is a seamless thong always invisible under clothing?

A seamless thong generally has less visible seams, but the edges, waistband and the fabric of your outerwear can still show through. Choose a colour that is close to your skin tone and check that the style doesn't have a wide elastic trim.

How do I care for shaping lingerie?

Follow the care label. Many of the shapewear bodysuits in this overview are designed to be hand-washed, without bleach, ironing, dry cleaning or tumble drying. Let the garment air-dry flat to preserve its shape and elasticity as much as possible.