POTASH – pH ADJUSTER & SCOURING AGENT

Chemical name: Potassium Carbonate (K₂CO₃) | Grade: Textile | Use rate: 3–10%

No natural-dye studio is complete without potash (Pottasche in German). This alkaline powder (K₂CO₃) is slightly stronger than soda ash and is traditionally used to raise the pH of dye baths and indigo vats, scour cellulose fibres, and intensify plant yellows such as weld by increasing alkalinity.

💡 Note: This product was previously listed as Soda Ash (Sodium Carbonate). We have updated the listing to Potash (Potassium Carbonate) to reflect the correct material.

Uses

• Boost pH in indigo, woad, or fructose vats
• Add to your scouring bath
• Intensify weld yellow and other plant yellows
• Balance acidic dye baths when needed

In a nutshell

• Material: Potash (Potassium Carbonate K₂CO₃)
• Function: pH enhancer & cellulose scour
• Dose: 30–100 g · L⁻¹ (3–10% owf) dissolved in hot water or dye liquor
• Compatibility: All natural dyes; indigo & woad vats
• Packaging: Resealable moisture-proof pouch
• Safety: Wear gloves & mask; store cool, dry, and away from acids

Basic directions

Dissolve the required potash in hot water (or directly into a hot dye bath) at 3–10%. Stir until clear, then add to the dye pot or fibre scour. For indigo vats, add potash after the pigment to adjust alkalinity before introducing a reducer.

Safety & storage

Potash is strongly alkaline. Avoid inhaling dust and protect eyes and skin. Store sealed and dry; keep away from children and acids. Dispose of effluent according to local regulations.

💡 Tip: Pair potash with our Natural Indigo Powder or Indigo Kits for a complete dye setup.

Potash vs Soda Ash Table

HYDROS – REDUCING AGENT FOR INDIGO / WOAD VATS
Chemical name: Sodium Dithionite (Thiox) | Grade: Textile | Use rate: ≤ 25 g per 10 L vat

Hydros—also known as sodium dithionite, thiox, or hydrosulfite sodium—is the fast, reliable oxygen remover used to bring indigo or woad vats into reduction. A quick sprinkle over the surface turns the liquor a yellow-green and readies it for dipping within about an hour. However, for best performance leave the vat for 2 days before dyeing.

Why choose our Hydros
• Consistent, high-purity powder for rapid vat activation
• Cost-effective alternative to spectralite (use a little more, save a lot)
• Fine, free-flowing granules supplied in a resealable pouch

Directions (10 L vat)

1. Set vat at 40 °C with indigo/woad and alkali already dissolved.

2. Sprinkle 25 g Hydros evenly over the surface. Always add Hydros to water—never water to Hydros.

3. Cover and wait ± 60 min. Vat should shift to yellow-green with a metallic film.

4. Stir gently, keeping air out, then begin dipping.

In a nutshell
• Function: Oxygen remover / vat reducer
• Other names: Sodium dithionite, thiourea dioxide, thiox, hydrosulfite sodium
• Compatibility: Indigo, woad, other vat dyes
• Typical dose: 2–5 g · L⁻¹ (max. 50g per 10 L)
• Packaging: Resealable moisture-proof pouch
• Safety: Wear gloves & mask; store cool & dry away from acids and oxidisers

Safety & storage
Keep sealed, cool and dry. Avoid inhalation of dust. Add powder to water—never the reverse—to prevent rapid exothermic reaction. Dispose of spent vats according to local regulations and keep away from children.

Need a full setup? Pair with our Natural Indigo Kit for a ready-to-dye bundle.

An Essential Ingredient for Indigo Dyeing

Hydrated lime, also known as calcium hydroxide, is a traditional material widely used in indigo dyeing and indigo production.

Produced by reacting lime derived from limestone with water, hydrated lime is a naturally occurring alkaline material with a long history of use in indigo processing, agriculture, building and water treatment.

Hydrated lime is commonly used in indigo reduction vats, including iron-lime vats and organic fructose vats, and plays an important role in traditional indigo extraction and production methods.

Product Details

Uses in Indigo Dyeing & Production

Hydrated lime is commonly used for:

• Iron-lime indigo vats
• Organic fructose indigo vats
• 1-2-3 and 1-3-2 indigo vat recipes
• Lime water preparation
• Indigo extraction and precipitation
• Shade enhancement before indigo dyeing
• Traditional indigo production methods

Lime Water for Indigo Extraction

Hydrated lime is often used to prepare lime water, an alkaline solution used during the extraction and precipitation of indigo pigment from indigo-bearing plants.

Lime water helps adjust pH during extraction and is an important component in many traditional indigo production methods.

Many dyers and indigo producers keep a supply of lime water on hand for both pigment extraction and indigo vat preparation.

Organic Indigo Vats

Many dyers use lime alongside fructose to create a simple and effective organic indigo vat.

A common recipe follows:

1 Part Indigo : 2 Parts Lime : 3 Parts Fructose

Combined with warmth, this creates a reduction vat based on sugar chemistry rather than fermentation.

Understanding Lime & Carbonation

Hydrated lime is produced from calcium carbonate (limestone).

When exposed to air, it slowly reacts with carbon dioxide and gradually converts back into calcium carbonate through a natural process known as carbonation.

For dyers, this means:

• Fresh lime is generally more active and predictable.
• Long-term exposure to air reduces effectiveness.
• Moisture accelerates deterioration.
• Proper storage helps maintain performance.

Storage Recommendations

• Keep tightly sealed when not in use.
• Store in a cool, dry place.
• Avoid prolonged exposure to air.
• Always use clean, dry utensils.

Stored correctly, hydrated lime remains usable for a long period, although freshness is always preferred for indigo vat preparation and indigo extraction work.

Learn More About Indigo Vats

Hydrated lime is used extensively throughout our Indigo Week resources and AppleOak indigo guides.

You can explore our indigo articles and tutorials here:

https://appleoakfibreworks.com/blogs/news

Join Our Free Natural Dyeing Community

Looking to deepen your natural dyeing knowledge and connect with other passionate dyers?

Start by joining our free Natural Dyers Academy community, where you'll find inspiration, discussions, resources, and opportunities to learn more about natural dyes, mordanting, fibre preparation, colour exploration, dye plant cultivation, and sustainable textile practices.

Join the free community here:

https://the-natural-dyers-academy.mn.co/share/Mz7coMI6VgbJMchB?utm_source=manual

Inside the community you'll find:

• Natural dyeing discussions and inspiration
• Helpful resources and learning opportunities
• Dye plant growing and harvesting tips
• Colour studies and recipe sharing
• Community support from fellow natural dyers
• Information about workshops, courses, and Academy membership options

If you'd like more structured learning, in-depth tutorials, workshops, and exclusive resources, you can also explore our full Natural Dyers Academy membership from within the community.

________________________________________________________________________________________________

Please Note

For textile, craft and technical use only.

Not intended for food, cosmetic or medicinal applications.

It is possible to create a vat from indigo, lime (calcium hydroxide) and over-ripe fruit such as bananas or dates that relies on the chemistry of the sugars* rather than fermentation of the fruit. But it’s easier to simply use fructose shared in

Michel Garcia’s 1-2-3 recipe. It’s very simple: One Part indigo, two parts lime and three parts fructose, plus warmth.

*Fructose and glucose found in ripe fruit are reducing sugars; ordinary sugar – sucrose – is not a reducing sugar. 

Traditional Chalk for Cellulose Mordanting & Natural Dyeing

Calcium carbonate, commonly known as chalk, has long been used in natural dyeing and textile preparation. It is particularly valued in traditional cellulose mordanting, where it is used during the dunging process to help stabilise aluminium acetate and prepare fibres for dyeing.

At AppleOak FibreWorks, we offer two sources of calcium carbonate:

Blanc de Meudon (France)

A traditional, finely milled chalk widely used in textile work, natural dyeing and decorative applications.

Burren Limestone Chalk (Co. Clare, Ireland)

Collected from limestone sourced near the Burren, one of Ireland's most iconic limestone landscapes. Rich in naturally occurring calcium carbonate, this minimally processed chalk performs beautifully for dunging and textile work.

As it is collected in its natural state, occasional small stones or mineral particles may be present. If required, simply sieve before use.

Product Details

Uses in Natural Dyeing

Calcium carbonate is commonly used for:

• Dunging after aluminium acetate mordanting
• Traditional cellulose mordanting processes
• Stabilising aluminium acetate within fibres
• Madder dye baths where water contains insufficient calcium
• Pigment and colour preparation
• pH adjustment in selected dye processes

Historically, dunging often involved cow dung. Today, calcium carbonate provides a cleaner and more practical alternative while serving a similar purpose in many mordanting systems.

Suggested Usage

Dunging Bath

• 1–2 teaspoons per litre of water
• or approximately 1% WOF (weight of fibre)
• or 1–3g per litre

Stir thoroughly before use, if you are using Burren stone, double the quantity.

Calcium & Madder

Calcium plays an important role in many madder dye baths.

Where local water is naturally soft and low in calcium, adding calcium carbonate can help encourage brighter, clearer red shades.

Choosing Between Our Two Options

Both products perform well in natural dyeing applications.

Choose Blanc de Meudon if:

• you prefer a traditional textile-grade chalk
• you want a consistently fine texture

Choose Burren Limestone if:

• you value locally sourced materials
• you enjoy working with minimally processed natural materials
• you appreciate a connection to place and landscape

Join Our Free Natural Dyeing Community

Looking to deepen your natural dyeing knowledge and connect with other passionate dyers?

Start by joining our free Natural Dyers Academy community, where you'll find inspiration, discussions, resources, and opportunities to learn more about natural dyes, mordanting, fibre preparation, colour exploration, dye plant cultivation, and sustainable textile practices.

Join the free community here:

https://the-natural-dyers-academy.mn.co/share/Mz7coMI6VgbJMchB?utm_source=manual

Inside the community you'll find:

• Natural dyeing discussions and inspiration
• Helpful resources and learning opportunities
• Dye plant growing and harvesting tips
• Colour studies and recipe sharing
• Community support from fellow natural dyers
• Information about workshops, courses, and Academy membership options

If you'd like more structured learning, in-depth tutorials, workshops, and exclusive resources, you can also explore our full Natural Dyers Academy membership from within the community.

Please Note

The Burren Limestone Chalk is a natural material and may contain occasional small stones or mineral particles. Sieving before use is recommended if a finer texture is required.

For textile, craft and technical use only.

Not intended for food, cosmetic or medicinal applications.

GUAR GUM ORGANIC
Use: Printing with Natural Dyes | Botanical Name: Cyamopsis tetragonoloba | Alternative to: Gum Arabic | Alternative Name: Guaran

Guar Gum is derived from organic guar beans and is an essential ingredient in natural dye printmaking. It is used to create a paste that works effectively with mordant dyes , allowing for precise application. Guar Gum thickens as it absorbs liquid, making it ideal for printmaking on textiles. Use a handheld blender or mixer to ensure even dissolution, and adjust the amount as needed for the desired consistency.

Key Features:

• 100% Organic Guar Gum
• Alternative to Gum Arabic
• Used for printing with mordant dyes & Indigo
• Thickens naturally for better application
• Helps create a mordant carrier for cellulose fabrics
• Best mixed with a handheld blender for smooth consistency

Function:
Guar Gum acts as a mordant carrier in natural dyeing. When combined with mordant-based dyes, it forms a rubber-like substance that can be drawn or printed onto fabric. Once dried, the gum must be removed with a Chalk and Wheat Bran solution, followed by a rinse. The fabric is then ready for dyeing. After dyeing, rinse thoroughly and boil with a small amount of organic washing-up liquid.

Basic Recipe for Guar Gum Mordant Carrier (for Cellulose Fabrics):

Ingredients for 100g:

• 10g Alum
• 5g Soda Ash
• 84g Vinegar (5% Acetic Acid)
• 1g Guar Gum

Storage & Usage:

• Once mixed, the solution will only last a couple of days.
• Store in the fridge and use fresh for best results.

Enhance your textile printing with this essential natural thickener, perfect for artists and dyeing enthusiasts.