MECHANICAL STRETCH VS SPANDEX FABRIC: A BUYER’S SPECIFICATION GUIDE

Start with the movement in the finished product

A jacket shoulder, trouser knee, workwear elbow and fitted cuff do not ask the same thing of a fabric. Mark each panel's movement direction on the pattern, and record what happens when the wearer reaches, kneels or bends. Decide whether the fabric is a shell, reinforcement, bonded softshell or lining before asking for a percentage. A high extension figure is not automatically better if the panel grows after use, a seam restricts movement, or the product loses the intended silhouette. For an outdoor jacket, weather protection, breathability and packability may matter alongside mobility; for a workwear shell, repeated movement and care may dominate. The design team should rank these needs instead of asking for a generic four-way-stretch claim.

• Name the exact garment position and intended movement.
• Specify warp, weft or multidirectional behaviour as applicable.
• Agree a minimum useful recovery and permitted residual growth only after a test method is chosen.

Compare the actual constructions, not the fibre labels

Three published Brilliant-Tex references show why a fibre-only comparison is misleading. PP14/R5FO65 is a 100% polyester, 75D mechanical-stretch pongee with a TPU-membrane route, published at 135gsm±5% and 145cm cuttable width. PP17/ROOO68-1 60C REC is a 100% polyester, 75D mechanical-stretch fabric bonded with polyester fleece, published at 250gsm±10gsm and 145cm cuttable width. PS1/E4FE67-1 60C lists a 96% polyester/4% spandex face with a TPU-membrane and polyester-fleece laminated route, published at 330gsm±5% and 145cm cuttable width. These are different finished systems, weights and intended starting positions. Their listings do not provide directly comparable stretch, recovery, ageing or wash results. Request tested swatches of the complete offered construction rather than ranking them by spandex content or hand feel.

Write an elasticity request that a laboratory can answer

The official ISO catalogue identifies ISO 20932-1:2018 as a strip-test route for fabric elasticity and ISO 20932-2:2018 as a multiaxial route. These are different approaches, not interchangeable numbers. Ask the buyer's technical owner and testing laboratory which method suits the garment question and the actual fabric, including whether a one-direction strip or surface deformation better represents the proposed panel. State specimen direction, conditioning, loading and rest procedure, cycles, required results and the acceptance rule. Identify whether the report covers the base fabric or the finished coated, laminated or bonded article. The public catalogue pages establish method scope and current status; they do not supply a Brilliant-Tex result or an acceptance threshold for your order.

Include the membrane, backing and seam route

A stretch face fabric is only one component of a softshell or waterproof garment. TPU membrane, bonding adhesive, fleece or interlock backing, coating, print and seam construction can change how the offered system moves or recovers. Ask for an assembled swatch that matches the intended commercial finish, then build a sample garment with the proposed seam placement and any sealing or bonding process. Check movement, appearance and care in that assembled state. Do not assume the face fabric's result transfers unchanged through lamination or that a fabric-level water-resistance entry proves the stitched garment will protect against rain. If a design change replaces the membrane, backing or seam process, reopen the approval rather than reusing an earlier result without review.

Control care, colour and bulk repeatability

Stretch and fit can be evaluated at the first sample stage, but a buyer also needs to know what happens under the garment's intended care conditions and across production lots. Agree whether the project requires post-laundering dimensional change, appearance, delamination and elasticity checks; do not presume one wash protocol suits every product. Record an approved physical reference, fibre blend, face and backing, nominal weight, cuttable width, shade and finishing route. Ask the supplier how it will identify a bulk lot and handle a deviation before cutting begins. Reconfirm the result if a different dyeing, bonding or finishing route is proposed. Published product specifications are screening data; availability, certification scope and the current production result require project-specific confirmation.

Send a useful enquiry instead of asking for 'stretch fabric'

A practical enquiry includes the garment type and panel position, target market, climate and activity, whether the shell needs a membrane or fleece backing, the approved reference or desired hand feel, colour, approximate weight and width, care route, sample quantity and bulk volume. State the movement direction and any measurable extension or recovery requirement if your technical team has already approved one; otherwise ask for a method proposal and clearly label the target as open. Include the required document stage and expected launch timing. Brilliant-Tex can compare these three public starting points and other relevant constructions, but will not infer fit, finished waterproofing, laboratory performance or supply availability from a catalogue name. Use the outdoor application page for the full product route, product search for alternatives, or the catalog request if several material systems must be considered.

• End product, panel position and movement direction
• Face, backing, membrane or coating route and care conditions
• Agreed test method, specimen state and approval owner
• Colour, width, quantity, sample timing and destination