Natural fibres are essential for use with natural dyes, these can be split into two categories: cellulose fibres and protein fibres. Cellulose fibres such as cotton, linen and hemp come from plants. Protein fibres such as wool and silk are derived from animals. It is important you know the difference as there are different methods of pre-treatment required. There is also a big difference in the way that cellulose and protein fibres receive dye.

Synthetic fibres, such as polyester and nylon which are made of plastic will not receive natural dyes well.

Giving your fabrics a deep clean, or a ‘scour’ enables you to have a blank canvas ready to receive dye. Many fabrics, especially cottons and linens carry a build-up of natural pectins and waxes, as well as dirt from processing and transportation. Scouring ensures that your fabric dyes evenly and the dye adheres more effectively to the fabric, therefore making your colour more lightfast and washfast. Get into the habit of weighing your dry fabric before scouring - it means you don’t need to let it dry fully after scouring in order to work out your mordant calculations.

For scouring cellulose fibres, use a ph neutral soap/synthrapol and soda ash

- Fill a large pot so that your fabric can easily move around

- For each 500g of fabric, use approximately 1-2 tsp synthrapol/ph neutral soap and 4 tsp soda ash

- Dilute in warm water, add your fabric and bring to a low simmer for approximately 1 hour

- Allow fibres to cool, then rinse thoroughly

For scouring protein fibres, use orvus paste/euclan/delicates ph neutral soap.

- Fill a large pot so that your fabric can move around

- For each 500g fabric use approximately 1 tsp soap

- Dilute in warm water, add fabric and slowly bring up to 60°C, holding there for approximately 1 hour

- Turn gently and regularly but do not agitate

- Care must be taken to avoid felting wool

- Allow fibres to cool, then rinse thoroughly

Protein fibres need to be treated with a bit more care, they don’t respond well to being ‘shocked’ in and out of hot and cold

Mordants are hugely important to ensure long-lasting and effective colour with most adjective dyestuffs. The type of mordant you use will affect the shade obtained from your dyestuff and its wash/lightfastness. There are many options to choose from when pre-preparing your fabric, from metal salt mordants, to plant mordants to natural binders. It is also important to understand what mordants you are using in relation to the fabric you have chosen to dye. We recommend experimenting and doing some research on mordanting if you are keen to continue your natural dye journey, but the below recipes are the most basic and effective methods to get you started.

*BEFORE YOU BEGIN - IMPORTANT SAFETY INFORMATION*

Although naturally occurring, metal salt powders should still be handled with care. Please use gloves and a mask when handling these fine powders and make sure to store them away from children and pets. We recommend that any pots or tools used for mordanting, are not used in food preparation going forward.

For cellulose fibres, there is an optional tannin process followed by an aluminium acetate bath. The tannin helps the aluminium acetate to more effectively adhere to the cellulose fibres but is not totally necessary. For protein fibres, the most widely used mordant is aluminium sulphate which is sometimes simply referred to as ‘alum’.

MORDANTING FOR CELLULOSE FIBRES:

Step 1 - the tannin process

Tannins are naturally occurring in plants and have the ability to stabilize metals like alum and iron inside fibres, assisting in the process of mordanting cellulose fibres. There are many different types of plant-based tannins and which ones you decide to use, will affect the final colour of your fabric. There is an abundance of tannin options available locally in the form of barks, cones, seed pods, nuts and galls.

- Weigh your fabric (dry) and work out the recommended WOF (weight of fibre) for the tannin you are using. For this example we will use Oak Gall powder at 8% WOF.
- Dissolve in warm water and add to dye pot with enough warm water to cover your fibres, bring to somewhere between 45-60°C
- Add scoured, wetted fibres and let soak for 1-2 hours, stirring occasionally
- Remove fibres and gently rinse before heading to your aluminium mordanting process
You can allow the fibre to steep in the tannin bath for an additional 8-24 hours which will, in most cases, provide you with a deeper saturation of colour

Step 2 - mordant process

Aluminium acetate (AA) is just one of many metal salts used for mordanting cellulose fibres. It is a relatively modern mordant, with aluminium sulphate being used traditionally in combination with a tannin bath. AA generally provides a much better saturation of colour, (and used without tannin can provide very bright colours, although we recommend a pre-tannin to aid with light and washfastness). Use at 5-8% WOF.

- Dissolve your measured AA in warm water and add to dye pot with enough warm water to cover your fibres
- Add your scoured and pre-wetted fibre and let it sit between 40-60°C for 1-2 hours, stirring regularly
- Cool bath, remove fibres and chalk fix. Aluminum acetate must be fixed prior to dyeing to neutralise any remaining mordant. Add 50g of chalk (calcium carbonate) to 5 litres of warm water. Fully wet the fibre in this solution and wring out, before rinsing thoroughly. This solution can be reused for up to 10kg of fibre.

MORDANTING FOR PROTEIN FIBRES:

For protein fibres we recommend using aluminium sulphate, usually referred to as simply ‘Alum’ – this is the most common mordant used on
protein (animal fibres), but can also be used on cellulose fibres in coordination with a tannin bath. Use at 15% WOF.

- Dissolve your measured alum in hot water and add to dye pot with enough warm water to cover your fibres so that they can move around freely
- Add the scoured and pre-wetted fibre and bring slowly over 30 mins or so to 85°C for silk and 90°C for wool - stir gently every now and then but do not agitate
- Allow bath to cool, remove fibres and rinse well
- Allow to hang evenly over a non-reactive rod (stainless steel/plastic) until it stops dripping

Store the yarn or cloth in a damp white cloth for 24-48 hours, keep damp during the entire period. Once dry, fabrics can be stored indefinitely.

Dyeing with plants has been practised for thousands of years, mostly involving the immersion of plant matter in hot water to draw out colour. Most plants can yield colour, but some are more effective and longer lasting than others - we recommend doing a bit of research to avoid disappointment. Dyeing fibres naturally also means that resulting colours can vary due to elements such as climate, parts of the plant used, heating times, mordant types, the minerals in our water etc - this makes every piece unique.

CREATING YOUR DYE

The amount of dyestuff to WOF (weight of fibre) ratio will differ depending on what fabric you are using (protein fibres such as silk will receive dye much more diligently than cellulose fibres), the dyestuffs used and the shade wishing to be obtained. A good rule of thumb for a medium depth of shade is 50% for dried dye materials and 100-200% for fresh dye materials (if you are using extracts this will vary and we recommend doing some research prior).

- Cut up your plant material into smaller pieces for better extraction of colour. Add these to a suitably large pot (big enough for your fabric to flow freely) and slowly increase the heat.

- The temperature of your dye bath depends on what dyestuff you are using. Fresh flowers do not need excessive high heat, whereas tannin rich dyestuffs such as barks and nuts tend to need higher temperatures for longer. We recommend doing a bit of prior research beforehand to aid the effectiveness of your results.

- Heat for 1-2 hours (dyestuff dependent) with the option of leaving it to cool and macerate further overnight

- Strain out the plant material and add it to your compost or green bin

DYEING YOUR FABRIC

- Pre-heat your dyebath to around 40°C and add your pre-mordanted, wetted fibre to your dye bath (wetting the fibre in water prior to dyeing can help greatly with the saturation and evenness of your dye) and slowly bring the bath to desired temperature (dyestuff dependent)

- Stir the fibre frequently to ensure an evenness of dye saturation

- When you are happy with the colour, let the bath cool and remove the fibre from the dye, gently wringing out any excess liquid. In some cases, you can leave your fabric in the pot for an extra couple of hours or overnight to deepen the shade (remember the colour of fabric looks quite different when it's wet compared to it's final shade when fully dry)

- Rinse your fibre and hang to dry out of direct sunlight.

- If you wish, once your fabric is dry, you can allow the fabric to ‘cure’ for a further week or two before washing (this is considered to aid with colour retention)

- Cool wash with a pH-neutral soap and hang to dry away from direct sunlight