Upcycling With Botanical Dyes for Beginners

You cannot use botanical dyes with fully synthetic fabrics. Polyester, acrylic and nylon do not take up dyes well. Polycotton works but the results are variable.

‘Semi-synthetic’ Fabrics include rayon, tencel, lyocell, bamboo and so on. These fabrics are manufactured using an energy and chemical intensive process. They are basically derived from plants (wood, bamboo) And hence they will take up botanical dyes because they're technically natural fabrics.

The best fabrics to use are the fully natural fabrics, for example wool, silk, cotton, linen and hemp.

To dye fabrics with botanical dyes, you must first treat the fabric with a mordant. If you do not use a mordant the fabric will not bind to the dye. The most commonly used mordant is alum (aluminium sulphate).

There are a range of other mordants that can be used. If you research the topic, you will see that alum is the best mordant for wool and silk (known as protein fibres as they come from animal sources).

Cotton, linen and hemp are known as cellulose fibres because they come from plant sources. These fabrics can also be mordanted with alum. However the best results come from using aluminium acetate or other alternatives.

The kits that we sell only contain alum (aluminium sulphate) because we consider it the safest and easiest to use. Other alternatives come as a fine powder that can be a respiratory irritant and release strong fumes when mixed with water. If you prefer to use these stronger mordants for your cellulose projects, you can purchase these from Kraftkolour Online.

For an even better result on cellulose fibres you can add in one extra step – the use of a tannin bath before mordanting. See Kraftkolour online for information about tannins and to purchase tannin powders.

The weight of the fabric determines how much mordant and dye to use. If you purchase our kits, we have weighed out the ingredients for you. The only reason you might change the quantities is if you are working on a very small project, in which case you might split the ingredients and save some for another project.

If you are working with the raw ingredients and you must weigh them out yourself, you will need some basic maths skills and a calculator. Botanical dyes are calculated as a percentage of the weight of the fibre (known as the WOF). For example, if you have 100g of fabric and you want to dye it at 30%WOF, you would need 30g of dyestuff.

You might think that the concentration of the dye in the water is critical, but it is not. The most important thing is that you have enough dye for the amount of fibre that you have. You must also have enough water for the piece to move around freely and not get squashed up.

The particles of dye will find the alum that is on the fabric and they will bind together. This will happen regardless of how much water you have in the dye pot. Obviously, this principle only works up to a point. If you had a swimming pool full of water, the fabric and the dye will not be able to find each other.

Whether you are working with second-hand fabric or brand new fabric, you must wash it first. Brand new fabrics contain coatings added during the manufacturing process. Second-hand fabrics can be stained with food and dirt.

Wool and silk should be washed in a gentle washing solution (e.g. wool wash, softly for delicates). You can use a gentle machine cycle. Do not use washing soda.

Cotton, linen and hemp should be washed in hot water with washing detergent plus a tablespoon of washing soda. To really make sure of it you can wash it more than once.

Dissolve the alum in hot water. Use a large bucket or a large plastic container. Submerge the fabric in the solution. Try to get rid of the large air bubbles that will form. The best way to do this is to put a glove on and squeeze it and submerge it. Weigh the fabric down with a plastic or glass container. Leave for four hours minimum, or overnight. Move the fabric around from time to time while you are awake.

Don't try to mordant for any less time than four hours. This process determines the strength of the dye result, and its ability to withstand washing and fading in the sun.

It might seem counterintuitive to rinse the fabric after mordanting. Perhaps you are worried that you will wash off the mordant. However, if the mordant is not attached to the fabric by now, it never will be.

Unbound particles of mordant attach to the dye and pull it out of solution. If that happens, it will not be available to bind to the fabric. This is the rationale behind rinsing off the excess alum prior to dyeing.

After all this preparation, you are now ready to dye your fabric. This is not a one size fits all approach. The technique varies depending on the dye and the fabric that you are dyeing. Here here are some general rules about fabrics and dyes that you should keep in mind.

• · If you are working with a flower petal dye, (such as marigold or dyers chamomile), avoid excessive heat. If you boil it vigorously, it will become muddy and dull.
• · If you are working with madder (rubia cordifolia) this dye improves with the application of heat.
• · If you are working with the other kind of madder (rubia tinctorum), this dye becomes dull if you allow it to boil.
• · Remember that if you are working with wool, treat it the way you normally would trade it if you were washing it. In other words, be gentle When handling it and don't expose it to excessive heat.

A discussion of every aspect of different dyes is beyond the scope of this short article for beginners. Suffice it to say that as you plan your project you will need a recipe that is specific to the dye that you are using.

Fine herringbone wool silk shawl (75% wool/ 25% silk), mustard

• 1. Handwash in gentle detergent with lukewarm water
• 2. Dissolve alum in hot water in a large bucket. Soak shawl for 4 hours minimum (you can soak it overnight). Move it around from time to time. Don’t let it float. You can weigh it down with plastic or glass items, but don’t use metal items.
• 3. Rinse. At this point you can dye it immediately or allow to dry and use later.
• 4. Put marigold and walnut in a calico bag, secure with a peg. Bring to a very gentle simmer in a large pot of water for 45 minutes. Remove the calico bag.
• 5. Turn off the heat. Submerge the shawl and move it around. Remove it when the colour is good (this could be anywhere from a few minutes to half an hour). Rinse in cold water and dry it in the shade. Wait 2 weeks before washing with detergent.

Olive colour dye kit

• Weigh fabric. If you have a lot less than 150g, save some dyestuff for later. Machine wash at the hottest recommended temperature using washing soda plus washing detergent that is appropriate for your fabric. (If you are working with silk or wool, don’t use washing soda.)
• Dissolve alum in hot water in a large bucket. Soak fabric for 4 hours minimum (you can soak it overnight). Move it around from time to time. Don’t let it float. You can weigh it down with plastic or glass items, but don’t use metal items.
• Rinse lightly and set aside.
• Place marigold in a calico bag, secure with a peg. Bring to a gentle simmer in a large pot of water and simmer 45 minutes. Remove the calico bag.
• If you are working with delicate fabric you can now turn off the heat. Robust fabrics can tolerate a low heat during the dyeing process. Submerge the fabric and move it around from time to time. Remove it when the colour is strong (this could be anywhere from a few minutes to half an hour). Rinse lightly.
• Now for the tricky bit. Put half a teaspoon of iron in a large bucket of warm water. Submerge the fabric. It should change colour to a rich olive almost immediately. If it doesn’t, remove it, add a little more iron, and submerge it again. Once the colour has shifted, rinse thoroughly and machine wash the fabric to remove the iron (excess iron can coarsen and damage fabric.)