4. BioChromes¶

Introduction and Research¶

The Biochromes Week revolves around natural dyes and understanding their potential in sustainable design. It started with a global lecture that introduced us to the concepts of biochromes, dyes, and pigments. The focus was on learning how to extract colors from natural sources, modify them, and apply them to different types of fibers and textiles. This was followed by a local session with our instructor, Claudia, where we went deeper into the science behind the processes and experimented with various materials.

Biochromes are natural pigments or colors derived from plants, minerals, or other organic sources. They’ve been used for centuries to dye fabrics, but in today’s world, they hold even greater significance due to their role in sustainable practices. Unlike synthetic dyes, which can be harmful to the environment, biochromes offer a renewable and eco-friendly alternative for creating vibrant and beautiful colors.

My goals for this week were to: - Understand the basics of working with natural dyes.
- Explore how different modifiers affect the colors.
- Experiment with extracting pigments.

Through hands-on testing and experimentation, I aimed to uncover the creative possibilities of these natural materials while gaining a deeper appreciation for their versatility and sustainability.

Understanding the Science and Terminology¶

To begin working with natural dyes, we first needed to understand the underlying science and terminology. During the global and local lectures, we explored several key concepts that form the foundation of biochromes and natural dyeing processes. This knowledge was essential for ensuring that our experiments were not only creative but also effective and repeatable.

Dyes and Biochromes: These are natural pigments or colorants extracted from organic sources such as plants, vegetables, fruits, and even some minerals. Biochromes are unique because they offer an eco-friendly and sustainable alternative to synthetic dyes, which are often harmful to the environment. For example, onion skins produce warm yellows and oranges, cabbage can yield blues and purples depending on modifiers, and pomegranate peels provide rich earthy tones. Each natural source has its own characteristics and challenges, making experimentation both exciting and educational.
Mordanting: Mordants play a crucial role in the dyeing process. These substances act as a bridge, helping the dye molecules bond more strongly to the fibers. Without a mordant, many natural dyes would fade quickly or fail to adhere to the fabric. We learned about different mordants, including alum (which preserves the dye's brightness), iron sulfate (which darkens colors), and copper sulfate (which can create greenish hues). Additionally, we discovered that the choice of mordant not only affects the dye’s durability but also significantly influences the final color, allowing us to achieve a broader palette from the same dye source.
Scouring: This is the preparatory step that cleans and opens up the fibers, ensuring they are ready to absorb the dye. Scouring involves boiling the fibers in water with soda ash (sodium carbonate) or other cleaning agents to remove impurities like oils, waxes, or manufacturing residues. For plant-based fibers like cotton, a more intensive scouring process is needed, often involving boiling for up to an hour. Animal-based fibers like wool and synthetic materials like felt require gentler treatment, as high heat can damage them. This step is essential for ensuring even dye uptake and consistent results.
Fibers and Textiles: Understanding the different types of fibers was another critical aspect. Organic fibers, such as cotton (plant-based) and wool (animal-based), tend to work well with natural dyes because their structures allow for better dye absorption. Synthetic fibers, such as felt, can be more resistant to dyeing but still yield unique results when treated properly. We divided our fibers into two main categories—plant-based and animal-based—since each type interacts differently with the dyeing process. This distinction also informed how we approached scouring and mordanting.
Modifiers: Modifiers are chemicals or natural substances added to the dye bath to alter the final color. By using modifiers like alum, sodium carbonate, iron sulfate, and lemon juice, we could observe dramatic shifts in hues, even from a single dye source. For instance, an onion skin dye bath might produce a warm yellow, but adding iron sulfate could shift it toward olive green. These modifications expanded the creative potential of our experiments.

By gaining a thorough understanding of these concepts, we were able to approach the dyeing process with both creativity and precision. These foundational steps—scouring, mordanting, and modifying—are crucial for achieving consistent, vibrant, and lasting results in natural dyeing. This knowledge also set the stage for more advanced experimentation with pigments and other biochrome applications.

Group Dyeing Experiments with Onion Peels and Red Cabbage¶

We started our group experiments by creating dye baths from two common and accessible natural materials: onion peels and red cabbage. These materials are rich in natural pigments and provided us with an opportunity to explore how different modifiers influence the final colors.

Creating the Dye Baths¶

The process began by boiling the onion peels and red cabbage separately in water to extract their pigments. The onion peel dye bath produced warm golden-yellow tones, while the red cabbage dye bath was particularly interesting due to its sensitivity to pH changes. When modified with different substances, the red cabbage dye shifted hues dramatically, ranging from purples and blues to greens and even pinks. This vibrant range made it an excellent material for exploring the effects of modifiers.

Testing Modifiers¶

We experimented with a variety of modifiers, including:

Alum: Brightened the colors and fixed them more effectively to the fibers.
Sodium carbonate: Shifted the red cabbage dye to greenish tones.
Iron sulfate: Created darker, muted tones, especially with the onion peel dye bath.
Lemon juice: Lowered the pH of the red cabbage dye, resulting in pink and reddish hues.

This exploration allowed us to see how modifiers can be used to expand the color palette of a single dye source, making natural dyeing a versatile and creative process.

Scouring and Mordanting¶

To prepare the fabrics for dyeing, we scoured and mordanted them. Scouring involved boiling plant-based fibers like cotton in a soda ash solution to remove impurities and open up the fibers for better dye absorption. For animal-based fibers like wool and synthetic materials like felt, we used a gentler scouring process by soaking them in hot water.

Once scoured, the fibers were mordanted using alum, calculated based on the weight of the fabric (WOF). Mordanting is essential for improving dye fixation and ensuring vibrant, long-lasting results. This step was particularly important for testing how the dyes and modifiers interacted with different types of fibers.

Experimenting with Shibori Techniques¶

After preparing the fabrics, we experimented with some Shibori techniques to create patterns. I worked on a piece of cotton fabric, folding it into a square and tying it tightly with cotton thread. Additionally, I secured one side with a metal clip, which acted both as a binding tool and as a modifier, interacting with the dye bath to alter the color where it touched the fabric.

The tied fabric was submerged in the onion peel dye bath, allowing the warm golden hues to penetrate selectively. When I removed the fabric and untied the threads, I was thrilled to see the beautiful patterns that had formed. The areas that were tightly bound resisted the dye, creating light patches, while the metal clip left a distinct mark where it had darkened the color through its chemical reaction with the dye.

These experiments yielded some visually striking results and demonstrated the potential of combining traditional techniques like Shibori with natural dyeing. The process was both creative and educational, providing a hands-on understanding of how dyes, modifiers, and techniques can work together to produce unique outcomes.

Testing with Pomegranate Dyes¶

A. Dye Preparation¶

To create the dye bath, I started with dried pomegranate peels, a rich source of natural pigments known for their earthy, warm tones. The process involved several steps to ensure the dye was properly extracted:
- First, I crushed the dried peels using a hammer to break them into smaller pieces.
- Next, I used a mortar and pestle to further grind the peels into finer particles, increasing the surface area for pigment extraction.
- The crushed peels were then boiled in water to release their pigments. To enhance the extraction, I blended the mixture using a hand blender while it was still hot.
- After boiling, I filtered the dye bath using a piece of fabric to remove the solid residues and obtain a smooth liquid.
- Finally, I divided the dye bath into smaller portions to test the effects of different modifiers.

This process resulted in a vibrant and concentrated pomegranate dye bath, ready for experimentation.

B. Modifier Testing¶

With the dye bath prepared, I moved on to testing various modifiers to observe how they altered the colors. Using small portions of the dye bath in petri dishes, I experimented with:
- Alum: Brightened the dye, producing greenish tones.
- Sodium Carbonate: Shifted the color to darker, more muted hues.
- Iron Sulfate: Produced darker, earthy shades, giving the dye a greenish-brown tint.
- Copper Sulfate: Added subtle green undertones to the dye.
- Lemon Juice: Lowered the pH, resulting in a slightly redder hue.
- Combinations of Modifiers: These created complex shades and added depth to the colors.

The results of the modifier testing were fascinating, as the same dye bath produced a wide spectrum of colors. This highlighted the versatility and creative potential of natural dyes.

C. Scouring and Mordanting¶

To prepare the fibers for dyeing, I followed the scouring and mordanting process: - Scouring: Plant-based fibers such as cotton fabric, cotton rope, and cotton thread were boiled for one hour in a solution of soda ash (3 tablespoons in a pot of water) to remove impurities. For animal-based fibers like wool and synthetic materials like felt, I soaked them in hot water without boiling to avoid damage.
- Mordanting: I calculated the Weight of Fabric (WOF) to determine the amount of mordant needed:
- For the plant-based fibers (209.4g), I used 10% alum, equaling 20.94g.
- For the animal-based and synthetic fibers (127.5g), I also used 10% alum, equaling 12.75g.
The fibers were soaked in their respective mordant solutions and heated gently to ensure the mordant was evenly absorbed.

This preparation step was crucial for achieving consistent and vibrant results during the dyeing process.

D. Dyeing Process¶

Once the fibers were scoured and mordanted, I proceeded with dyeing:
- I heated portions of the dye bath, including both unmodified and modified versions, and placed a piece of each fiber (cotton fabric, cotton rope, cotton thread, wool yarn, and synthetic felt) into the baths.
- Each fiber was left to soak for an hour, allowing the pigments to penetrate and bond to the material.

The results were striking. The unmodified dye bath produced warm, earthy tones, while the modified dye baths yielded a variety of shades:
- Iron Sulfate: Darkened the fibers to create deep, earthy greens and browns.
- Alum: Enhanced the brightness and clarity of the colors.
- Sodium Carbonate: Softened the tones to lighter and more pastel-like hues.

Comparing the fibers showed how different materials and modifiers interact with the same dye bath, resulting in unique outcomes. This experimentation revealed the creative possibilities of natural dyes and the importance of preparation in achieving desired results.

Testing with Saffron Dye¶

A. Dye Extraction and Modification¶

For this experiment, I created a small batch of dye using saffron, known for its vibrant yellow pigment. The process was straightforward: - I soaked a small quantity of saffron in hot water, allowing the color to diffuse and create a concentrated dye bath.

Once the dye bath was ready, I tested it with various modifiers to observe any potential color changes. Using petri dishes, I added the following modifiers to separate portions of the dye bath:
- Alum
- Sodium Carbonate
- Copper Sulfate
- Lemon Juice

However, unlike the dramatic color changes observed with the pomegranate and red cabbage dye baths, the saffron dye showed minimal changes. The modifications resulted in only slight variations in the darkness of the color, with no significant shifts in hue. This indicated that saffron’s color is relatively stable and less reactive to modifiers.

B. Dyeing Process¶

Despite the limited results with modifiers, I proceeded to test the saffron dye bath on the same range of test pieces I had prepared for the pomegranate dye:
- Cotton fabric
- Cotton rope
- Cotton thread
- Wool yarn
- Silk

Each piece had been scoured and mordanted prior to dyeing to ensure good absorption of the dye. I submerged the fibers into the saffron dye bath and let them soak for about an hour. After removing and drying the test pieces, I observed the results:
- The cotton-based fibers (fabric, rope, and thread) took on a soft yellow tone, though less vibrant compared to other dyes.
- The wool yarn absorbed the color slightly better, resulting in a warmer and richer yellow.
- The silk produced the brightest and most luminous yellow, showcasing saffron's natural affinity for animal-based fibers.

While the saffron dye bath yielded subtle and consistent results, the experiment highlighted its limitations in terms of color variety. It also reinforced the importance of understanding each natural dye's unique properties and behavior, especially when working with modifiers and different types of fibers.

Extracting Pigments¶

A. Understanding the Science¶

Pigment extraction is a process that transforms liquid dyes into solid, concentrated pigments. This is achieved through a chemical reaction between alum and sodium carbonate, which causes the dye molecules to precipitate out of the liquid. The resulting pigment can be used in various applications, such as creating paints or printing patterns, and allows for the long-term preservation and reuse of natural dyes. This process is particularly valuable in sustainable design, as it reduces waste and extends the functionality of the dye beyond fabric dyeing.

B. Process for Creating Pigments¶

To extract pigments, I worked with the leftover dye bath from my experiments with pomegranate peels and saffron. The steps were as follows:
1. Measuring the Dye Bath: I weighed the remaining dye bath to calculate the necessary amount of alum and sodium carbonate.
2. Adding Alum: I added alum at a concentration of 10% of the dye bath’s weight. This initiated the precipitation process.
3. Adding Sodium Carbonate: Next, I added sodium carbonate at 5% of the alum's weight. This reaction caused the pigment to form and settle at the bottom of the container.
4. Collecting the Pigment: After allowing the mixture to sit, I filtered the liquid to separate the solid pigment from the remaining solution.

The resulting pigment was a deep, earthy shade that reflected the original color of the pomegranate dye bath. It had a smooth and vibrant consistency, making it suitable for further applications.

C. Creating a Stamp¶

To explore the possibilities of using the extracted pigment, I decided to create a custom stamp for printing patterns:
1. Designing the Stamp: Using Rhino, I designed a unique stamp inspired by organic shapes and patterns.
2. Laser Cutting the Stamp: I laser-cut the design into MDF, creating a durable and reusable stamping tool.
3. Stamping with the Pigment: I mixed the pigment with a binding agent to create a paste suitable for stamping. Then, I used the stamp to print patterns onto fabric and paper.

The results were satisfying, with the stamped patterns showcasing the natural, earthy tones of the pigment. This experiment demonstrated how natural pigments can be creatively repurposed for artistic and practical applications, adding another dimension to the possibilities of biochromes.

Final Thoughts and Conclusion¶

Reflecting on the experiments and testing during Biochromes Week, I gained valuable insights into the fascinating world of natural dyes and pigments. The process of creating dye baths from onion peels, red cabbage, pomegranate peels, and saffron allowed me to explore the diversity and richness of colors that nature offers. Modifying these dye baths with different substances revealed how small chemical changes can produce an array of hues, expanding the creative potential of natural dyes.

One of the most rewarding aspects was learning the importance of scouring and mordanting to prepare fabrics for dyeing. These steps were crucial for achieving consistent and vibrant results across different fiber types. Experimenting with Shibori techniques added an extra layer of creativity, showcasing how traditional methods can be paired with natural dyes to create unique patterns and designs.

The pigment extraction process was another highlight, as it opened up new possibilities for preserving and repurposing dyes. By transforming leftover dye baths into solid pigments, I could create tools like custom stamps for printing, demonstrating the versatility of natural pigments in both artistic and practical applications.

Lessons Learned¶

The preparation of fibers (scouring and mordanting) plays a significant role in the success of natural dyeing.
Modifiers are powerful tools for expanding the color palette but require careful experimentation to achieve desired results.
Natural dyes like pomegranate and red cabbage are highly responsive to modifiers, while others like saffron are more stable and limited in their variability.
The process of extracting pigments adds value and extends the usability of dye baths, making it a sustainable practice.

Potential Applications¶

The knowledge and techniques gained from this week can be applied in various ways:
- Incorporating natural dyes into future projects for sustainable and eco-friendly textile design.
- Using pigment extraction to create paints, prints, or other artistic applications.
- Combining traditional dyeing techniques like Shibori with modern tools like laser-cut stamps to create innovative designs.
- Exploring the use of natural dyes in educational kits or workshops to inspire others about the possibilities of biochromes.

Overall, this week was a deep dive into the intersection of science, art, and sustainability, offering a foundation to explore the creative potential of natural dyes and pigments in future projects.