The category where the fabric is the product
Yoga wear, underwear and socks are the smallest items in an oopbuy clothes order and the ones you notice most when they are wrong. A leggings that goes transparent in a squat or a sock that slides down inside a shoe cannot be fixed by styling. These are fabric problems, and fabric is exactly what a photo cannot show.
This guide covers what to look for in the listing, what to ask the agent, and how to check base layers in QC.
Yoga leggings: the three numbers
Stretch and recovery
Good activewear fabric has four-way stretch and, more importantly, recovery — it returns to shape after being stretched. A blend of nylon and elastane is the common standard; polyester blends are cheaper and less breathable. The elastane percentage matters: around 15 to 25 percent is typical for high-stretch leggings, though construction affects the feel as much as the number.
Opacity
Thin, light-coloured leggings can go sheer when stretched. This is the single most common complaint about budget activewear. Look for a fabric weight in the listing, and prefer darker colours if you cannot verify. In QC, ask for a photo of the fabric stretched, or at least a close-up held against light.
Seam construction
Flatlock seams lie flat against the skin and reduce chafing. A crotch gusset — a separate panel — improves fit and durability. Both are visible in listing photos and are good indicators of whether the maker understands activewear.
| Feature | Why it matters | How to check |
|---|---|---|
| Four-way stretch | Movement without restriction | Composition and listing description |
| Recovery | Keeps shape after washing | Higher elastane; buyer notes |
| Opacity | Confidence in motion | Fabric weight, darker colours |
| Flatlock seams | Less chafing | Visible in close-up photos |
| Gusset | Better fit and durability | Visible in flat-lay photos |
Fit for leggings and sports tops
Compression wear is meant to be close, so measurement tolerance is smaller than for a hoodie. Compare waist and hip measurements with the chart, and check the inseam: a full-length legging and a 7/8 length differ by several centimetres, and the listing title often does not say which.
Sports bras are the hardest item to buy remotely. Band size and cup coverage both matter, and charts vary. If you are unsure, buy one first rather than three. Look for a description of support level and whether the straps are adjustable.
Underwear: what actually matters
Underwear is cheap, light and easy to ship, which makes it a sensible add-on. The things that matter are fabric and construction, not branding:
- Cotton — breathable, comfortable, holds shape reasonably. The safe default.
- Modal or viscose blends — very soft, drape well, but stretch out faster.
- Synthetic performance fabrics — quick-drying, good for sport, less breathable for all-day wear.
- Gusset — a cotton-lined gusset is standard and worth checking for.
- Waistband — a covered elastic that does not roll is the difference between comfortable and not.
Sizing runs small in many listings. Compare the waist range in centimetres rather than the letter, and if you are between sizes, choose the larger for comfort.
Socks: the most underrated item in a parcel
Socks cost almost nothing to ship and are the first thing to wear out. The useful distinctions:
- Cotton — comfortable, absorbs moisture, dries slowly. Good for everyday.
- Merino wool — warm, odour-resistant, temperature-regulating. Excellent for cold weather and travel.
- Synthetic blends — durable and quick-drying. Good for sport, can hold odour.
- Bamboo viscose — soft and breathable, less durable than cotton.
Check the cuff: a ribbed cuff that stays up is the main quality signal. Also check the toe seam — a flat toe seam is noticeably more comfortable inside a tight shoe. Sizing is usually by shoe size range; if you are at the top of a range, size up.
Buying base layers in a parcel
Base layers are ideal parcel filler. A few pairs of socks, underwear and a light sports top add maybe 300 to 500 g and round out an order at very little shipping cost. They also let you test a seller's sizing cheaply before committing to a larger purchase.
Do not over-order, though. Ten pairs of socks is not a wardrobe strategy, and the money is better spent on one piece you will actually wear. Our list guide suggests a sensible ratio of basics to main pieces.
Care
Activewear should be washed cool and never with fabric softener, which clogs the fibres and reduces stretch recovery. Air dry rather than tumble drying, because heat degrades elastane. Underwear and socks can be washed warmer, but check the label. Merino socks last much longer with cool washing and no dryer.
QC for base layers
- Seams flat and even, especially flatlock joins on leggings.
- Elastic waistbands not twisted and evenly gathered.
- No snags or pulls in the knit.
- Sizing label matches the order.
- For leggings, ask for a stretch photo if opacity is a concern.
Base layers are cheap to replace but annoying to return, because the shipping usually costs more than the item. Getting the fabric and size right the first time is the whole game. For the layers above, see the tee guide and the clothing overview.