More Sustainable Shoe: Asking the right questions

When we talk about fashion & sustainability the most complex product to approach is footwear.

A guide on how to make sustainable shoes

Understanding the complexity of footwear

When we talk about fashion & sustainability the most complex product to approach is footwear. This complexity arises from the fact that the product may consist of 35 to 40 different components with various compositions. We can almost compare shoes to a car.

“Shoes are not shirts” as stated on the FDRA website. If you truly want to gain a basic yet comprehensive understanding of what is inside a pair of shoes, you can check in their guide, I suggest saving it for the end of the reading to maintain your motivation and positive learning vibes.

Designing for Innovation and Trends

First of all, you should ask yourself: What type of brand or product do I want to make?

If it is a brand that wants to be innovative and has always the latest trend that unfortunately may become obsolete after 6 months, it prompts you to consider the product's end-of-life implications, because it will be thrown away pretty soon. In this case, you need to focus on a few points:

  • Design for disassembling with a simple construction and just a few materials
  • Use compostable, biodegradable and low-impact materials.
  • Are you able to take back the product at the end of life?
  • Are there composting facilities that can biodegrade your product?
  • Can the product be recycled?

Prioritise for Timeless and Durable Products

In the opposite scenario, where your brand is positioned as timeless and you want your product to last long and also be reparable there are other key priorities:

  • Are the materials durable enough?
  • Follow the factory and product development experts to design a durable and reparable product.
  • Is the manufacturing of the product of good quality to ensure a long lifespan?
  • Identify the critical areas and components of the shoes and create guidelines for easy repair.
  • How can you take back the product and facilitate its transfer to a second or third owner? Consider partnering with a renting platform.

Categorizing shoes based on components

Now that you have defined the type of brand and product you want to create, let's delve into its complexity. We can categorize the type of product into three macro categories based on the shoes' components: 1 to 3 components, 4 to 8 components, and more than 8 components.

1 to 3 components:

If your product consists of 1 to 3 components, you are likely dealing with items like pool slides, flip flops, or shoes designed with a single material. Most of the time, these products are made with EVA and synthetic rubber, meaning plastic. While this may not be an ideal starting point, there are variations in plastics. Consult your supplier or manufacturer to determine if there are any biobased components in the plastic. For example, some EVA may incorporate sugarcane or other feedstock. However, be cautious and inquire about the exact source of the feedstock; if sugarcane is sourced from intensive farming without biodiversity considerations, it may not be an improvement. An alternative worth exploring is BLOOM FOAM, derived from harvesting algae in polluting lakes. While you may be limited to including no more than 20% of it in the total composition, it offers a more environmentally friendly impact.

4 to 8 components:

With 4 to 8 components, the situation changes, especially with simpler shoes like sandals that don't have many components. Here, you can focus on the few materials that make up 80% of the shoes by weight. Ask your supplier about more sustainable alternatives based on the brand type you defined. If using leather for a more durable product, prioritize Leather Working Group tanneries and inquire about the origin of the skin to avoid leather from deforested areas. Explore innovative and less impactful tanning technologies, as mentioned in the blog "A guide on how to find your leather and tannery partner" to optimize the use of leather. If utilizing cotton, aim for certified GOTS/OCO organic or GRS/RCS recycled cotton. Similarly, if using polyester, opt for GRS/RCS recycled options; the cost won't be significantly higher than virgin polyester. Consider the manufacturing process and strive to use only water-based glue. While the footwear industry previously used solvent-based glue, it was discovered that solvents are hazardous to workers, causing damage to the brain and memory. There are now limited water-based glue alternatives that you can rely on.

More than 8 components:

The most complex and the majority of shoes on the market have more than 8 components, possibly reaching up to 40 components. Guaranteeing that all these components are sustainable is a challenging task, but don't be discouraged. Take it step by step – you can eat an elephant beat by beat.

Start by focusing on the main materials: upper, lining, insole, and outsole. The outsole is often overlooked due to its technical nature, but it constitutes the majority of the shoe, accounting for 45% to 65% of the product's weight. While EVA can be used in the midsole (refer to alternatives for 1 to 3 components), for the rubber outsole, there are more options. Usually, rubber is the outer part in direct contact with the ground, with critical technical specifications. Natural rubber is an option, but ensure it is FSC certified, as much rubber comes from intensive farming without biodiversity, harming the soil. Emerging solutions like SOLUM, a biobased "regenerative" material, or Pliant from Natural Fiber Welding are in the early stages, so thorough investigation and compliance with your specifications are advised before adoption.

For upper materials and lining, follow the same sustainable practices adopted for leather and textiles. Insole foam is typically a component that can be either recycled with slight compromises in comfort or biobased, as seen in products like Fates from Evoco. Other components inside the shoes maintain the product's shape and longevity, constituting about 10%-15% of the product's weight. While often synthetic, they have recycled alternatives at a relatively cost-neutral price. The factory must use water-based glue to ensure high-quality sticking, assembling, and longevity standards for the product.

Balancing Sustainability in Shoe Production

Understanding the complexity involved, it becomes apparent how challenging it is to label a shoe as sustainable. Each component contributes to the environmental impact of the product. Moreover, due to the product's complexity, there are no certifications available that can substantiate sustainability claims until the finished product. After finding the right balance of sustainable materials and components, your focus should shift to communication. Share information about what the materials are and how they are made, and provide certification standards at the material level to support your claims—not at the product level.

As the complexity increases, meticulous attention must be paid to the materials and production process. Therefore, sustainable design implies a simple and minimal design with only a few components, striking the right balance between aesthetics and durability.

Conclusion: Embracing Sustainable Design

Within the intricate dance of sustainable shoe production lies an opportunity for transformative change. Embrace the challenge, simplify the design, and let curiosity lead. The journey towards a truly sustainable footprint is a story waiting to unfold—one step at a time.

Published: 10/01/2024


Nicolò Giusti
Nicolò Giusti
BIO: Nicolò is an innovative and sustainable material specialist working in the fashion industry for more than 15 years. His passion for traditional materials but also for innovative solutions brought him to create the Sustainable Academy, a community that supports students, entrepreneurs and fashion companies to be more sustainable and avoid greenwashing.
"I really believe in the power of collaboration. Sharing and learning is the only way we can get to the next level. Why waste time protecting ourselves when we can use it to improve?"