Supplex for sewing clothes: selection methods, care and techniques for working with elastic fabrics
Supplex is an elastic knitted fabric for clothing that stretches well and holds its shape due to the content of elastane (lycra). It is more common when trying to buy supplex fabric from St. Petersburg, like cotton-polyester or mixed knitwear.
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i recommend choosing biflex composition 80–85% polyamide + 15–20% elastane with a density of 200–250 g/m& sup2; and four-way stretch of 120-180% – this combination is suitable for leggings, leotards and dancewear and provides a balance of elasticity and strength.
- Properties: density 180–260 g/m², shrinkage coefficient during the first wash 3–5%, retained elasticity after 30 washing cycles – about 90% with gentle mode; the surface can be matte or slightly shiny, the surface dries quickly and can withstand contact with chlorine if properly impregnated (check the supplier’s certificate).
- Sewing Tips: Use 70-90 Ballpoint needles, polyester sewing thread, 2. 5-3mm stitch width or knit zigzag; for professional seams we recommend an overlocker of 3–4 threads and a stack of 0. 7–1. 0 cm; for the bottom hem, a double needle 2. 5–4. 0 mm is convenient, and when working with thin supplex, set the tension below average and use a walking foot.
- Care: wash at 30 °C on a delicate cycle with a mild detergent, without bleaches or conditioners; dry flat or on a hanger away from direct heat; ironing at low temperature through a damp cloth (maximum 110 °C) or without ironing, so as not to lose elasticity; Avoid dry cleaning and strong solvents.
- Application and selection of density: for swimsuits, choose 180–210 g/m& sup2; with high chlorine resistance; for sports leggings – 210–250 g/m& sup2; with reinforced reverse suture fixation; for compression products and corsets – 240–260 g/m& sup2; with increased elastane content and additional fixing tapes.
Biflex for sewing clothes: properties, care and application
According to physical characteristics: supplex usually consists of 70–85% polyester and 15–30% elastane, transverse elongation 40–80% (measured in a relaxed/tensioned state), return to original length > 90% after stretching is removed. The material dries quickly, has poor air permeability compared to natural fabrics, and abrasion resistance is high, but chlorine-containing environments reduce the strength of elastane by about 20–40% over a season of use.
Care: wash at 30°C on a delicate cycle, turning the product inside out; use detergent for synthetics, do not use bleaches or conditioners (they destroy elastane), dry flat on a towel or hanging on a hanger without stretching the seams, dry iron at 110 °C through a layer of fabric or gauze. Dry cleaning is possible only according to the manufacturer’s label; Do not treat with chlorine bleach.
When sewing, use Ballpoint or Stretch needles 70/10–90/14, polyester rubber thread (through 100% polyester), “narrow zigzag” stitch. 2. 5–3. 5 mm or special elastic loop stitch; for hemming, use a double needle 3. 0–4. 0 mm. Seam margin 7–12 mm, seam processing – 3-thread overlock or flat seam for minimum thickness. Do not stretch the fabric when stitching – this will lead to waves.
Recommendations for cutting and processing: cut with a sharp roller knife on a dense backing, secure with clips instead of frequent pins, make a fixing stitch on the necks 3-5 mm from the cut, if necessary, hem with a thin structure thermal tape to preserve the shape of the waist and cutouts.
Examples of application with exact parameters: swimwear – 180–220 g/m², elastane 18–22%; sports tops and overalls – 200–260 g/m& sup2;, elastane 20–24%; dance costumes and stage clothing – 160–240 g/m& sup2; with letterpress printing; compression leggings – 240–300 g/m& sup2; with elastic return. For products in contact with chlorine (swimming pool), please request the option marked “chlorine resistant”. in the specification.
Quality control when you decide to buy supplex fabric: ask for a 20 x 20 cm sample to check density and stretchability, do a wet test for abrasion and dye fastness, look at the edge twist – it shows the winding and composition, measure the stretch manually. Reviews sometimes contain the remark “only there is garbage here” – avoid sellers with such comments and check the return policy, yes, ask for a certificate of conformity for the composition and sewing characteristics.
If you decide to buy biflex fabric wholesale, request color certificates and a trial run (at least 5 meters). Recalculate shrinkage after the first wash and record a seam length tolerance of +1–2% for mass production.
How to choose the composition and density of biflex for swimsuits, sportswear, and stage wear
- Swimsuits: Choose a higher percentage of elastane (18–22%) for a snug fit and quick shape recovery. A density of ≥200 g/m² is recommended if you require an opaque layer when wet. For full-length styles, lining with 80–120 g/m² tricot or travel fabric is recommended, layering them in the cups and front to reduce stretch across the chest. Sportswear: Focus on density and elastic modulus—for tights and leggings, 20–30% elastane and 240–320 g/m²; for tank tops, 15–20% elastane and 170–230 g/m². Look for fabrics labeled “4-way stretch” and high elasticity; for compression, compare the feel on the body at 25–40% stretch.
- Stage costumes: Prioritize abrasion resistance and color rendition—a density of 260–340 g/m² and 25–35% elastane will provide a dense, shiny look and a better fit. For appliqués and sequins, use a high-strength base, and reinforce seams with double stitching and adhesive tape at stress points. Pre-purchase testing: After ordering a 20×30 cm sample, perform a stretch test by stretching it 20-30% and then releasing it. The fabric should return to its original shape almost completely within 10-30 seconds. Wash the sample 5 times on the recommended cycle, assessing shrinkage and loss of elasticity. Test the fabric’s wet behavior: at a density of
- Sewing parameters: Stretch/jersey needles 70/10 for fine fabrics and 80/12-90/14 for heavy fabrics; elastic stitch (narrow zigzag 2-3 mm or special stitch for knits), stitch length 2-3 mm; threads – polyester with a core; edging elastic bands 7-25 mm, depending on the piece; overlock threads 3-4 for durability.
- Transparency and density guidelines: If you require 100% opacity when wet, choose a density of 200 g/m² or higher, or use a two-layer construction on problem areas (front, thighs). For a bondage and shaping effect, aim for a higher percentage of elastane and a density of > 260 g/m².
- Cutting and machine finishing techniques for biflex: needles, stitches, seams, and thread tension
- Cutting: tools and techniques
Cut on one flat surface without stretching the parts; for curves, use sharp scissors or a roller cutter. The surface must be flat – supplex fabric is prone to displacement when tensioned.
Cutting: tools and techniques
- Layering: cutting in 1 layer will reduce deformation when cutting complex patterns; When cutting in 2 layers, control the alignment of the elastane pattern/direction.
- Markings: water-based markers or sticky chalk string; Avoid glue markers that leave a shine.
- Allowances: standard 7–10 mm for swimsuits and sportswear, 10–15 mm for stage costumes with frequent reworking of seams.
- Needles, threads and machine settings
- Needles: Ballpoint/Stretch – 70/10 for thin supplex, 80/12 for medium density, 90/14 for dense latex or multi-layer parts. Change the needle every 4 to 6 hours or when you skip stitches.
Needles, threads and machine settings
- Double needles: 2. 5–3. 0 mm distance between needles for bottom stitching; use Stretch twin needle and matching lower tensioner.
- Loopers/overlockers: 3‑ or 4‑thread overlocker for main seams; differential feed 0. 9–1. 2: 0. 9 for over-assembly, 1. 1–1. 2 to prevent waviness.
- Tension and stitch settings (origin points):
- Home sewing machine (three-step zigzag stitch): length 2. 0–2. 5 mm, zigzag width 1. 5–2. 5 mm, upper thread tension 3–4 (base scale 0–9).
Narrow zigzag for elastic joints: width 0. 5–1. 5 mm, length 1. 0–1. 8 mm.
- Straight stitch: Use only when reinforced (stretch stitch or stretch stitch). Length 2. 0–2. 8 mm, low sewing speed.
- Overlock: stitch length 2. 5–3. 2 mm, differential 0. 95–1. 15, adjust looper tension so that the loops lie evenly on the cut.
- Flatlock stitch: stitch length 2. 5-3. 5mm, for hem use a 2- or 3-needle station with 40/2 threads and a gray/contrast color bottom chain thread.
- Monitoring and adjusting tension – a quick reminder:
- If the loops of the upper thread are visible on the wrong side, loosen the upper thread tension or tighten the tension of the bobbin thread.
If the bobbin/looper stitches are visible on the right side, reduce the tension on this thread.
- If clicking or skipping occurs, check the needle (it’s the right type and not dull) and reduce the sewing speed.
- If the seam is stretched, reduce the presser foot pressure and use an underlay/interlining or tape to stabilize the seam (including 3-5 mm elastic tape for shoulder seams).
- Types of stitches and where to use them:
- 3-Step Zigzag – the main stitch for strong, elastic seams (back, inseam). Maintains stretch and load-bearing strength.
Narrow Zigzag and Stretch Stitch – for fine seams and decorative topstitching.
- Flatlock/Faux Flatlock (serger + topstitching) – a seam without thickness, suitable for fitted suits and competition apparel.
- Flatlock Hem – a neat, elastic hem without thickening. Seam sealing/taping (hot-melt elastic tapes) – use when a smooth outer surface and waterproof seams are needed.
- Common defects and quick solutions:
- Stretched edge – Reduce presser foot pressure, place a thin paper backing under the seam, and increase the differential on the overlocker.
- Puckering – Reduce the upper thread tension or increase the stitch length by 0. 2–0. 5 mm.
Skipped stitches – Change to a new Stretch/Ballpoint needle and check the needle insertion direction.
- Thick bulges at intersections – Make small notches along the seam allowance and pull slowly, use reinforcing tape.
- Practical care tips for biflex: washing, drying, stain removal, and restoring elasticity
- Wash biflex at 30°C on a delicate cycle or by hand with a liquid neutral detergent. Use cold or warm water (maximum 30°C), liquid detergent without bleach or enzymes, and a delicate cycle, or hand wash, patting and not shaking vigorously.
- Before washing, close zippers and Velcro fasteners, turn the garment inside out, and place it in a laundry bag. Do not overload the drum; wash with similar colored items; spin at 800 rpm or hand wringing is sufficient.
Do not use conditioners or standard fabric softeners regularly: they form a film that reduces elasticity over time. A short rinse with 1 tablespoon of hair conditioner per 1 liter of water is acceptable once every few months, followed by a thorough rinsing. This is an infrequent restorative treatment, not a routine care routine.
Removing oil and cosmetic stains: apply a drop of dishwashing detergent, rub in with light rubbing movements for 10-15 minutes, then rinse with warm water. For sunscreen residue, soak in a solution of oxygen bleach (sodium percarbonate powder) according to the manufacturer’s instructions for 30 to 60 minutes, then rinse.
Remove blood stains with cold water and enzyme (delicate) products; hot water will set the stain. Gently moisten ink and alcohol stains with isopropyl alcohol from the inside, blot without rubbing on the fabric. For glue or varnish, freeze the area and scrape gently with a plastic scraper.
Do not use acetone, chlorine bleach or aggressive solvents – they destroy elastane. Before using any chemicals, test on an inconspicuous area.
Drying: Gently squeeze out the water, roll it into a terry towel to speed up absorption, and spread the product on a flat horizontal surface to dry in the shade. Direct sunlight and hot sources (radiators, hair dryer on hot, dryer on high cycle) reduce elasticity.
Ironing: Avoid direct contact of the iron with the surface. If you need to iron, use a warm iron through a cotton pad on the wrong side or steam at a distance of 10–15 cm. Do not exceed the temperature for synthetics.
Restoring elasticity with partial loss: soak in warm (not hot) water, add 1 tbsp. spoon of soft conditioner per 1 liter, gently stretch the item into shape and leave to dry on a flat surface. Repeat the procedure no more than once every 2–3 months; If the fabric is constantly losing shape, the elastane is most likely damaged and the area or fabric needs to be replaced.
- Storage: fold flat, avoid heavy objects on top and prolonged hanging on hangers, so as not to stretch the shoulder areas. Keep away from solvents, oils and perfumes.
- Carefully cut off small defects and pills with fabric scissors or use a knitwear trimmer without tugging at the material. When repairing seams, use elastic threads and a zigzag or knit stitch.
- Supplex for sewing clothes: selection methods, care and techniques for working with elastic fabrics
