Yarn & Materials Developer

The Inside Job; Metropolitan Borough of Solihull; On-site; GBP 45,000 - 65,000; Full time

Job summary

Gymshark is seeking a Yarn & Materials Developer to drive end-to-end development and industrialisation of seamless yarns, knit structures, and material platforms from concept to bulk production.

You will work across disciplines to translate consumer needs into technically feasible, commercially scalable, performance-led seamless products, with a minimum onsite presence of four days per week at Gymshark HQ and a commitment to sustainability and quality.

Qualifications

• Minimum of 3 years' experience in material development, yarn development, seamless development, performance fabric development, or related technical product development.
• Strong technical knowledge of seamless materials, fibres, yarns, and knit constructions.
• Good understanding of seamless circular knitting technology, preferably Santoni or equivalent machinery.
• Knowledge of yarn covering methods, yarn draw-in processes, feeder allocation, plating, yarn pathing, and yarn tension principles within seamless circular knitting.

Responsibilities

• Developing and industrialising seamless yarns, knit constructions, and material platforms across multiple product categories.
• Translating consumer needs such as sculpting, support, compression, softness, breathability, opacity, sweat management, and comfort into innovative yarn and knit solutions.
• Supporting fibre selection, yarn specification, elastane construction, covering methods, feeder allocation, yarn pathing, and machine set-up decisions to achieve desired performance outcomes.
• Collaborating closely with Seamless Technical Development, Knit Programming, Product Development, Design, Colour, and Sourcing teams throughout the development process.
• Partnering with yarn suppliers and seamless manufacturing partners to develop proprietary and commercially scalable seamless material solutions.
• Supporting the development of seamless knit architectures including rib, mesh, jacquard, tuck, float, plating, engineered ventilation, waistbands, under bust structures, and body-mapped compression zones.
• Building supplier capability through technical collaboration, performance reviews, and continuous improvement initiatives.
• Supporting seamless-specific testing and validation programmes, including stretch and recovery, compression, opacity, dimensional stability, abrasion resistance, pilling, colour fastness, and wash durability.
• Interpreting laboratory, wear trial, and supplier testing data and converting findings into clear technical action plans.
• Integrating sustainability considerations into yarn, material, and product development to improve environmental performance without compromising product quality or functionality.
• Contributing to commercial engineering decisions involving yarn cost, stitch complexity, machine time, lead times, and manufacturing efficiency.
• Maintaining accurate technical documentation, including yarn specifications, knit construction records, test reports, supplier capability data, and development libraries.
• Managing and developing seamless yarn, stitch architecture, body-mapping, and material platform libraries.
• Supporting the creation of Gymshark-owned seamless platforms, proprietary knit structures, technical claims, and supplier-exclusive developments.

Skills

Seamless development

Yarn development

Material development

Knit constructions

Lab testing

Sustainability

Supplier collaboration

Communication

Documentation

PLM systems

Santoni machinery

Travel willingness

Tools

Santoni seamless machinery

Job description

Help shape the future of Gymshark Seamless innovation.

At Gymshark, great seamless products start with exceptional yarns, materials, and technical innovation. We're looking for a knowledgeable and detail-orientedYarn & Materials Developer to support the end-to-end development and industrialisation of seamless yarns, knit structures, and material platforms, from initial concept through to bulk production.

This role is critical in ensuring our seamless products meet the highest standards of performance, quality, durability, fit, innovation, and sustainability while supporting the successful delivery of our seasonal collections. You'll work closely with Seamless Technical Development, Knit Programming, Product Development, Design, Colour, Sourcing, Quality, yarn suppliers, seamless manufacturing partners, and machine technicians to develop industry-leading seamless products that help strengthen Gymshark's position as a global leader in performance apparel.

WHAT YOU'LL DO.

As aYarn & Materials Developer, you'll play a key role in translating product vision into technically feasible, commercially scalable, and performance-led seamless products, ensuring development milestones are achieved on time and to the highest standard.

Key responsibilities include:

Developing and industrialising seamless yarns, knit constructions, and material platforms across multiple product categories.

Translating consumer needs such as sculpting, support, compression, softness, breathability, opacity, sweat management, and comfort into innovative yarn and knit solutions.

Supporting fibre selection, yarn specification, elastane construction, covering methods, feeder allocation, yarn pathing, and machine set-up decisions to achieve desired performance outcomes.

Collaborating closely with Seamless Technical Development, Knit Programming, Product Development, Design, Colour, and Sourcing teams throughout the development process.

Partnering with yarn suppliers and seamless manufacturing partners to develop proprietary and commercially scalable seamless material solutions.

Supporting the development of seamless knit architectures including rib, mesh, jacquard, tuck, float, plating, engineered ventilation, waistbands, under bust structures, and body-mapped compression zones.

Building supplier capability through technical collaboration, performance reviews, and continuous improvement initiatives.

Supporting seamless-specific testing and validation programmes, including stretch and recovery, compression, opacity, dimensional stability, abrasion resistance, pilling, colour fastness, and wash durability.

Interpreting laboratory, wear trial, and supplier testing data and converting findings into clear technical action plans.

Integrating sustainability considerations into yarn, material, and product development to improve environmental performance without compromising product quality or functionality.

Contributing to commercial engineering decisions involving yarn cost, stitch complexity, machine time, lead times, and manufacturing efficiency.

Maintaining accurate technical documentation, including yarn specifications, knit construction records, test reports, supplier capability data, and development libraries.

Managing and developing seamless yarn, stitch architecture, body-mapping, and material platform libraries.

Supporting the creation of Gymshark-owned seamless platforms, proprietary knit structures, technical claims, and supplier-exclusive developments.

WHAT YOU'LL NEED.

Essential Experience & Skills

• Minimum of 3 years' experience in material development, yarn development, seamless development, performance fabric development, or related technical product development.
• Strong technical knowledge of seamless materials, fibres, yarns, and knit constructions.
• Good understanding of seamless circular knitting technology, preferably Santoni or equivalent machinery.
• Knowledge of yarn covering methods, yarn draw-in processes, feeder allocation, plating, yarn pathing, and yarn tension principles within seamless circular knitting.
• Ability to assess how fibre composition, yarn selection, stitch architecture, elastane construction, and machine settings influence fit, compression, recovery, opacity, handfeel, durability, and production consistency.
• Strong understanding of seamless knit structures including rib, mesh, jacquard, tuck, float, plating, engineered ventilation, and body-mapped support zones.
• Good understanding of garment technology, seamless construction, fit, grading principles, and body-zone performance requirements.
• Strong knowledge of laboratory testing and commercial testing standards for performance activewear and seamless products.
• Ability to interpret laboratory testing, wear trial results, and supplier performance data to identify opportunities and resolve technical challenges.
• Good understanding of colouration, dyeing, and finishing processes relevant to seamless yarns and garments.
• Experience working directly with yarn suppliers and seamless manufacturing partners throughout the development lifecycle.
• Strong understanding of sustainable practices within yarn, material, and product development.
• Excellent communication and stakeholder management skills, with the ability to collaborate effectively across internal and external teams.
• Strong problem-solving skills and the ability to proactively identify risks and propose practical solutions.
• Excellent attention to detail, organisation, and technical documentation standards.
• Proficiency in Microsoft Office and PLM or similar product lifecycle management systems.
• Ability and willingness to travel when required.

Preferred

• Experience working with Santoni seamless suppliers or equivalent circular knitting manufacturers.
• Experience developing women's and/or men's seamless activewear products.
• Knowledge of sculpting, compression, body-mapping, engineered ventilation, and support zone technologies.
• Experience working with covered elastane, air-covered yarns, textured yarns, recycled polyamide/polyester yarns, and performance synthetic yarns.
• Experience managing yarn libraries, stitch architecture libraries, material platforms, or innovation programmes.

Onsite Collaboration: Due to the hands-on and highly collaborative nature of the work within our Product & Supply Chain team, we have a minimum expectation of FOUR days per week onsite at our Gymshark HQ. This ensures we can work closely together to innovate, problem-solve, and deliver world-class products for our community.

Disability Confident Committed
We’re proud to be a Disability Confident Committed employer and want to encourage anyone with a disability to apply for a role at Gymshark. We offer an interview to candidates with disabilities or long-term conditions who meet the minimum criteria for the role.