Fiber Guidelines

Sustainability is at the core of our fabric. We spend a lot of time thinking about what type of fibers we use because it is one of the first steps in making a product. The type of fiber we use can have varying effects on the environmental impact of a product - from how one cares for a garment, how long it lasts and how one disposes of it. That’s why we created a list of the fibers that we use and the fibers we don’t use with data from various life-cycle assessments and the Textile Exchange Preferred Fiber Market Report.


A life-cycle assessment is a methodology that is used to assess the environmental impact of products at all stages of the product life cycle. It starts with the raw material extraction and usually goes to the end of life of a product. Take a pair of Boyish Jeans made with certified organic cotton, it’s life-cycle assessment would start at the farm level, move to the ginner, yarn spinner, weaver, dyehouse, printer, to the factory where it’s produced. It also includes all the transportation in between.

Our “Yes” fibers are eco-friendly fibers-- that have a lower environmental impact than most fibers in terms of energy use, water consumption, greenhouse gas emissions, etc. Learn more about each of our “yes” fibers below.

Yes List

Organic Cotton

Organic cotton has all the great qualities of conventional cotton without the negative impact on the environment. It is actually grown using methods and materials that will have a positive impact on the environment and the farmers who grow it. Organic cotton production works to replenish and maintain the soil with crop rotation and prohibits the use of GMO seeds and toxic pesticides. 

According to a life-cycle assessment that was conducted by Textile Exchange in 2014, growing cotton organically has the potential to create various environmental savings. For example, a pair of boyish jeans made with organic cotton saves 8,978 gallons of water compared to a pair of jeans made with conventional cotton6

We’re committed to using 100% certified organic cotton from the Organic Content Standard (OCS) and/or Global Organic Textile Standard (GOTS). OCS sets requirements for the certified organic input and chain of custody with the goal of increasing organic cotton production. GOTS has some of the highest standards in the industry that cover both ecology & labor conditions for textile processing and manufacturing. Third party auditors like Control Union, help to ensure that these standards are implemented throughout the supply chain.

Recycled Cotton

Recycled cotton requires no additional textile waste and very little resources compared to conventional and organic cotton. According to the Sustainable Apparel Coalition’s Higg Index, recycled cotton is the most sustainable cotton fiber which is the reason why you'll often see this fiber included in many of Boyish jeans compositions as Boyish recycles their own cutting waste back into their fabrics. 

There are two types of recycled cotton: pre-consumer & post-consumer recycled cotton. Pre-consumer recycled cotton is cotton that is made from textile waste like fabric scraps. Post-consumer recycled cotton is cotton that is made from old clothes or textiles and is repurposed into new fabric. Recycling cotton can be done either mechanically or chemically which usually classifiies if it is considered upcycling or downcycling. Mechanical recycling involves shredding textiles which tends to generate something of lower value (aka downcycling). But this isn’t always the case. Our recycled cotton is blended with Tencel™Lyocell or Refibra™ which helps reinforce the fiber and gives it similar strength to a conventional yarn--meaning that we can use it again to create something new. Chemical recycling on the other hand, breaks textiles down to the fiber level which means it can be used to create something of the same quality or better (also known as upcycling).  

Certain companies like Re:newcell and Evrnu are leading the way in upcycling used garments to make pulp that can be fed back into the textile production cycle. Lenzing is also working to close the loop by incorporating pre-consumer textile waste to create virgin fibers with Tencel™ x Refibra™ Lyocell, learn more about it below.  

Recycling cotton is one approach towards a more circular textile industry. Recycled cotton is certified through the Recycled Claim Standard (RCS) and Global Recycled Standard (GRS).

Tencel™ Lyocell

TENCEL™ Lyocell is one of the most sustainable options right now. It’s made of sustainable wood pulp primarily from eucalyptus trees that are FSC certified, PEFC certified, or controlled so they’re not sourced from ancient or endangered rainforests. Compared to conventional cotton, TENCEL™ uses just a fifth of the land and a tenth of the water to produce, thanks to its closed-loop manufacturing process.

Read more about it here.

Sources: Lenzing LCA, Lenzing Sustainability Report

Refibra™ Technology

TENCEL™ x Refibra™ Lyocell uses the same closed-loop manufacturing process as TENCEL™ Lyocell but incorporates a significant amount of fabric scraps to create new virgin TENCEL™ Lyocell fibers. Fabric scraps are generally pre-consumer waste that ends up on the cutting floor that would otherwise be thrown away. About 15% of a company's fabric that is supposed to be for clothing ends up as fabric scraps. That’s a lot of fabric going to waste if you think about how many clothing companies there actually are. Lenzing is working to close the loop and create a more circular economy with Refibra™. 

Read more about it here

Stretch Fibers

Spandex or elastane are synthetic fibers that are usually made from fossil fuels like crude oil as a by-product from petroleum refining. Although we don’t love to use synthetic fibers we make an exception for spandex because a lot of times our clothes actually need a little bit of give to help with the way the fabric is constructed. We try to limit our elastane use to 2% or less of the total garment composition. This is in line with our commitment to the Ellen MacArthur Jeans Redesign Project and the maximum amount allowed for recycling cotton from companies like ReNewCell


But not all spandex is derived from fossil fuels--there are now recycled and bio-based options on the market. We are starting to explore including these in our collections. For example, we are working with one of our denim mills, Candiani on incorporating more natural rubbers into our fabrics which would replace our need for petroleum based fibers. Candiani recently developed a new technology coined COREVA™, which uses a plant-based yarn to replace conventional synthetic yarns. It is made when organic cotton is wrapped around a natural rubber core which allows for the creation of stretch denim without the use of fossil fuels.

Our “No” fibers tend to have a bad rep when it comes to their environmental impact--whether it’s increased water consumption, dependence on fossil fuels, harmful chemicals, etc. these are fibers that we like to avoid.

No List


Conventional Cotton

Conventional cotton is known as being the dirtiest crop on earth. Most conventional cotton tends to be genetically modified which either makes it resistant to certain herbicides or helps fight off certain pests. However GMO cotton seeds come with their own problems which tends to promote the use of more chemicals. According to the WWF, Cotton makes up approximately 11% of the pesticides sales and 24% of insecticides sales. Not to mention that conventional cotton uses approximately 5,283 gallons to produce 2.2 pounds of cotton11. That’s equivalent to about 2,600 gallons of water per jean. 

Conventional cotton's use of chemicals and consumption of water leads to soil erosion and pollution of the ground and waterways--leading to negative lasting impacts on the environment. These chemicals destroy the soil that the cotton is planted in. This creates a negative cycle where the chemicals weaken the plants, which in turn weaken the soil, leaving room for more pests which means the use of even more pesticides that continues to weaken the soil. This cycle continues until the land becomes infertile resulting in finding even more land to yet create another cycle.   

BCI Cotton 

Conventional cotton isn’t the only cotton we don’t allow. Better Cotton Initiative, BCI Cotton, is a global non-profit organization with a large “sustainable” cotton program. However in 2018 we recently learned that BCI does not actually regulate their cotton processes including factory conditions for their workers, child labor, GMO cotton, and more. They run as an NGO out of Switzerland with no accountability on their mass market approach or impact. Read more about it on their website for BCI.


Viscose (rayon) is the third most common fiber used in the world. It is a man-made cellulosic fiber which is just a long way of differentiating the fiber from natural fibers like cotton. Viscose is made from wood pulp that usually comes from various trees which are then put into a chemical bath where the wood is broken down so it can eventually be used to create fiber. There are two big issues with viscose--the first being deforestation and the second the chemically intensive process that is used to convert the wood into fiber. 

One ton of viscose consumes up to 4.5 tons of trees15. Yes it is true that viscose is mainly made from trees that grow fast on low grade land but cutting down trees still contributes to deforestation. Not to mention that approximately 30% of rayon used in the fashion industry comes from endangered or ancient forests13

Viscose production also uses a highly toxic process to convert the wood into fiber. A 2017 report found that multiple manufacturers in different areas of the world (China, India, Indonesia) were dumping untreated wastewater into local waterways5. Chemicals that are used in the production of viscose can be highly toxic if absorbed through inhalation, indigestion, or skin contact. Carbon disulfide, one of the chemicals used is known to cause heart disease, birth defects, skin conditions, and cancer.


Synthetics are some of the most common fibers found in our clothes--from dress shirts to workout clothes. Synthetic fibers like polyester, nylon, acrylic, etc. are made from fossil fuels which makes it highly carbon and energy intensive. Synthetics can carry carcinogens and neurotoxins from the materials and dyes which can have serious health effects. This can also be seen with California’s Proposition 65 which requires businesses to provide warnings about significant exposures to chemicals that cause cancer, birth defects or other reproductive harm. This can even be seen on brand and retailer’s websites. Try searching some common brands and see what you can find. 

Not to mention they are not biodegradable which means that they will continue to live in the ecosystem long after they break down. One of the largest lasting impacts synthetics have is when they break into tiny little pieces called microfibers that pollute our waterways and eventually end up in our food.This happens when garments made out of synthetics are agitated or washed, they shed microfibers (>0.5 um) which are too small to be picked up in water. filtration plants thus ending up in our oceans1. A study done in 2011 indicated that one polyester garment can shed up to 1,900 per wash2. Once they are in the ocean they act as magnets to other harmful chemicals like DDT and become food for plankton and slowly make their way up the food chain.

It’s important to note that synthetic materials are needed for certain garments aka windbreakers, ski jackets, etc, but we don’t think they belong in clothes that are heavily washed like your favorite pair of jeans, t-shirts, or sweatpants. 

In context: Another 22 million mt of synthetic fiber fragments could be added to the ocean between 2015 and 2050 if business-as-usual continues2. The annual amount of primary synthetic fiber fragments released from textiles is estimated at around 500,0002 mt per year.

Recycled Synthetics

Recycled synthetics are slightly better than conventional synthetics because they divert waste from landfills and help reduce the dependence on fossil fuels. There are various feedstocks that can be used to make recycled synthetics like fishing nets, carpet, and plastic bottles. But even though recycled synthetics help eliminate certain things from going to the landfill they still shed tiny bits of plastic called microfibers which persist in the environment for millions of years. Recycled synthetics are good fiber options for waterproof and technical materials, like windbreakers. But we don’t think they should be used for casual goods (for instance: T-shirts, Sweatshirts, or Fleece Jackets) or anything that touches direct skin as they still hold many carcinogens, neurotoxins, and volatile organic compounds (VOC's). Our skin is our largest organ, and it needs to be treated as such.


On top of purchasing certified fibers, we think it’s important to set rules for chemicals used along the way; from the beginning of fiber production to after our clothes are made. That’s why we have two lists of restricted chemicals : Manufacturing Restricted Substance List (MRSL) & Restricted Substance List (RSL).


MRSL is a list of chemicals that are banned prior to clothes being made. It sets rules for what can be used to produce our clothes and how much we allow. Our MRSL is in line with the Zero Discharge of Hazardous Chemicals (ZDHC) MRSL V2.0. Check out the full version of the MRSL here.


RSL is a list of chemicals that are banned after our clothes are made. It makes sure that no unwanted chemicals were added to the production of our clothes and they are safe for you to wear. Our RSL list is in line with AFIRM Group industry level standards. 

Check out the full RSL list here.

In addition to our MRSL & RSL, we try to use fibers that are certified with some of the highest standards like GOTS. Check out our sustainability section to read more about it.

In addition to our MRSL & RSL, we try using fibers that are certified with some of the highest standards like GOTS. Check out our sustainability section to read more about it.


1. Bruce, N., Hartline, N., Karba, S., Ruff, B., Sonar, S., & Holden, P. (2016). Microfiber pollution and the apparel industry. University of California Santa Barbara, Bren School of Environmental Science & Management (accessed 19 Aug 2016).

2. Galloway, T., & Thompson, R. (2011). Accumulations of microplastic on shorelines worldwide, sources and sinks. Environmental Science and Technology, 45, 91759179.

3. Hartline, N. L., Bruce, N. J., Karba, S. N., Ruff, E. O., Sonar, S. U., & Holden, P. A. (2016). Microfiber masses recovered from conventional machine washing of new or aged garments. Environmental science & technology, 50(21), 11532-11538.

4. Higg Materials Sustainability Index, supplier LCAs, and LCA databases.

5. Markets, C. (2017). Dirty fashion: how pollution in the global textiles supply chain is making viscose toxic. Changing Markets.

6. Textile Exchange Preferred Fiber & Materials Market Report 2020.

7. Potential savings in Blue Water Consumption (Irrigation i.e. water removed from, but not returned to the same drain- age basin.) See 'Summary of Findings', page 14-15.

8. Quick Guide To Organic Cotton.

9. Rissanen, T. (2005). From 15% to 0: Investigating the creation of fashion without the creation of fabric waste. Creativity: Designer meets Technology Europe.

10. Shen, L., & Patel, M. K. (2010). Life Cycle Assessment of Man-Made Cellulose Fibres. Lenzinger Berichte, 88, 1-59.

11. Singh, Z., & Bhalla, S. (2017). Toxicity of Synthetic Fibres & Health. Advance Research in Textile Engineering, 2(1), 1-5.

12. World Wildlife Foundation,

13. Lenzing 2017 & 2018 Sustainability Reports.

14. McCullough, DG. (2014). Deforestation for Fashion: Getting Unsustainable Fabrics out of the Closet. Guardian News & Media Limited. 15.

15. Cernansky, Rachel. (2020). Fashion’s Steep Climb to Sustainable Viscose. Vogue Business, Vogue.

*Disclaimer: TENCEL™, REFIBRA are trademarks of Lenzing AG.