Dyeing wool: the art of colouring cloth for suits

Dyeing wool: the art of colouring cloth for suits

Dyeing is a fundamental process in the world of textiles, and of course at Dormeuil, as colour gives character and elevates the finished garment. When fabrics and fibres are infused with vibrant colours, they may carry another part of the story behind the cloth required for suits, like this winter’s Millennial®Genesis collection, for example. This intricate and fascinating process involves various techniques and methods in order to achieve the desired shade. In this article, we will delve deeper into the world of fabric dyes, exploring the various techniques, innovations, and considerations that come into play when creating richly coloured cloth for wool suits.

A process where each step makes a difference

Fabric dyeing involves multiple stages, each of which contributes to high-quality wool suit fabrics. To display consistent and vibrant coloration, fabrics need to undergo rigorous and careful handling.  Dyeing is a complex and intricate process which is also why it is fascinating!

Preparing the fibre for dyeing

Dyeing may be carried out in the form of fibre, yarn or fabric. All have to go through the pre-treatment to be rid of any impurities such as oils, waxes, dirt, and other substances. This step aims to create an ideal surface for dye absorption. With wool, this typically involves processes like scouring which removes natural impurities. Bleaching, washing and thorough rinsing also ensure optimal absorbency. 

Which fabric dyes are used to colour wool for suit fabric? 

The answer depends on various factors, including the desired colour, fabric type, and end-use requirements. Two main categories exist: natural dyes and synthetic dyes. Natural colours may be extracted from plant or animal sources, while synthetic dyes are based on a mix of chemicals, they are man-made. Synthetic dyes were a great innovation in the textile industry and greatly improved colour fastness, which designates the dyed cloth’s resistance according to several factors like wear, care, and exposure to sunlight. 

The selection of fabric dyes, whether natural or synthetic, plays a vital role in determining the colour palette and its intensity. Different application methods exist and are selected to ensure even and uniform colour distribution.  Today’s textile industry mostly uses synthetic dyes due to their broader colour range, colour fastness, and ease of application.

How are dyes prepared and applied? 

A dye bath is prepared by dissolving the selected dye in water or a specific liquor. The concentration of the dye solution depends on the desired colour intensity. Other additives, such as levelling agents, dispersants, and pH regulators, may also be added to homogenise dye distribution and heighten compatibility with the fabric.

There are several methods for application, including exhaust dyeing, continuous dyeing, and pad dyeing. Exhaust dyeing is the most common method and involves immersing the fabric in the dye bath and heating it to a specific temperature. The fabric remains in the bath until it reaches the desired colour depth, and the colour is absorbed by the fibres. Continuous dyeing is employed for large-scale production, while pad dyeing utilises a padded roller to apply the solution evenly onto the fabric. These methods are used for dyeing yarns as well as fabrics.

How can we be sure the fabric dyes are fixed? 

Once the fabric has absorbed the dye, it needs to be fixed to ensure the colour becomes permanent and does not fade or wash out easily. Fixation is achieved through a process called steaming or thermal fixation. The fabric is exposed to high temperatures and steam, which helps the dye molecules bond with the fibres, enhancing colour fastness. Fixation is a critical step in the dyeing process, where the colour is made permanent through thermal or chemical treatments.

After dye fixation, the fabric undergoes an after-treatment stage to remove any excess dye or chemicals and improve its final appearance. This stage typically involves rinsing, soaping, and washing. When dyeing wool, like we do at Dormeuil, the steaming process is recommended. Rinsing and soaping may also help improve the fabric's hand feel and smooth onward processing. 

When is the dyed cloth truly finished? 

Finishing treatments can be applied to modify the fabric's properties and meet specific requirements, ranging from softness and durability to flame retardancy and water repellency. Possible treatments include softening, crease-resistance, water repellency, flame retardancy, or any other desired functional or aesthetic modifications. These processes are determined according to the fabric’s end purpose. 

Fun facts about dyeing wool

Due to wool’s unique characteristics, its dyeing process differs slightly from other textiles. The first thing to keep in mind is that it is a natural protein fibre, as it is derived from the backs of sheep, goats, alpacas, or cashmere goats. This chemical composition and structure is a bigger challenge to dye in comparison to synthetic fibres or plant-based fibres like cotton. Consider theses specifications: 

  1. Fibre preparation must take into account the natural oils, dirt, and other impurities contained in wool fibres. The scouring process, involving mild detergent or alkaline solution, is key to  improve dye absorption. Dormeuil applies fabric dyes to the wool top, which has been thoroughly cleaned and ensures homogenous absorption. 
  2. Wool can actually absorb a wide range of dyes, both natural and synthetic! Usually, manufacturers favour acid dyes for higher compatibility. Acid dyes are water-soluble and contain acidic groups that bond more effectively with wool fibres.
  3. Wool is sensitive to heat and pH. Dyeing wool is best carried out at moderate temperatures to avoid shrinking or loss of natural elasticity. An acidic dye bath is set at a temperature below boiling point. Acid helps with dye absorption and maintains a suitable pH level for wool. 
  4. Dyeing wool may take longer compared to other fibres due to the fibre's complex structure. The dye molecules need sufficient time to diffuse and bond with the protein chains of the wool. Slow stirring or gentle movement in the dye bath, helps promote even dye distribution as long as no excessive felting or matting of the wool fibres occurs.
  5. Wool fabrics or yarns may benefit from additional post-dyeing treatments like softening or conditioning to enhance its hand feel and manage any potential stiffness. 

Wool's unique properties, such as its natural crimp, moisture-wicking ability, and insulation properties, make it a highly desirable textile. However, such properties also require careful handling and consideration during the process to preserve the integrity and performance of the wool fibres. By understanding the specific requirements and challenges of dyeing wool, manufacturers can produce beautifully coloured wool textiles that retain the fibre's inherent qualities and meet consumer expectations.

Dormeuil and dyeing wool

At Dormeuil, we pride ourselves in the consistent coloration of textiles so all three processes are chosen to best serve our wool suit fabric production. The many steps of the dyeing process go much further than simply adding colour; they also define a fabric’s sheen and special qualities. 

To ensure a homogenous treatment of colour and to preserve wool’s incredible natural properties, dyeing wool at Dormeuil is mostly carried out when the fibres are at the “wool top” stage.  This way, the strands are dyed in bulk prior to the spinning process

Some fabrics are dyed at the yarn stage. In this method, the spools of raw thread are immersed into dye baths once they are spun. 

Finally, some collections undergo dyeing once they are woven. In this process, textiles are processed in their natural colour and then dyed in an autoclave, a specialised equipment that creates a high-pressure environment with precise temperature monitoring to promote colour absorption.

Dormeuil uses responsible fabric dyes 

Today, the textile dyeing industry stands at the intersection of science, technology, and creativity. At Dormeuil, we strive to achieve a balance between aesthetics, precise coloration, durability and sustainability. We seek to integrate responsible dyeing methods into our collections every season. 

Mostly due to the chemicals and the volumes of water required, textile dyeing plays a significant role in the textile industry’s environmental impact. For decades, efforts have been made to develop eco-friendly dyeing processes, from the use of natural dyes and low-impact dyes to innovative dyeing techniques that minimise water and chemical consumption. 

Our  Echo & Tonik® Wool collections are certified Oeko-Tex. The Oeko-Tex Standard 100 certification is an independent system that tests and certifies textiles to ensure they are free from harmful substances, setting strict limits on the use of certain chemicals in textile production. Dyes must not contain harmful substances such as heavy metals, formaldehyde, phthalates, and other chemicals that can be detrimental to human health. This way, Dormeuil holds rigorous safety standards in producing a cloth required for suit making that is tested for its chemical composition. It also is verified to be free from substances that could cause harm or irritation when in contact with the skin.

As consumers, we interact with dyed textiles every day, appreciating the vibrant colours and intricate patterns that enrich our lives. Colour can also play a role as a social marker, which we saw in the story of the blue blazer.  Understanding fabric dyes and the overall process gives us a new appreciation of the craftsmanship and skill that goes into creating the fabrics we cherish.