Experimental Botanical Print with Leaves using Alum Mordant

Print with leaves found in the garden or out on a walk; explore, experiment and take notes! Creating these Botanical Prints is so satisfying as each experiment will give you a different result.  You can find further information about this technique from our Blog post Botanical Printing – an overview or search the internet to discover different methods for extracting the colour.`

Prints made with leaves on fabric

Botanical prints using Cotinus Coggygria “Royal Purple” leaves and Lilac leaves on silk and cotton fabric

A length of cotton and a length of silk fabric were first soaked in a solution of Alum mordant. It is important that your fabrics are dirt and grease free as this will affect how the Alum and colour is absorbed. Diluted Synthrapol is an excellent scourer and will ensure that your materials are clean. See more about PFD (prepared for dyeing).

Preparing the Fabric with Alum

The Alum mordant from George Weil comes in crystal form and needs to be dissolved in water. Make up a solution of Alum water using 2 heaped teaspoons of Alum to 500ml of water (you can make larger amounts depending on how much fabric or paper you wish to print). It is best to dissolve the Alum in about 100ml of hot water and then thoroughly stir in the final 400ml of cold water.

Soak your fabric in the Alum mordant water for 10-15 minutes, remove and squeeze out the excess liquid.

Colour results will vary depending on the fibre content of the fabric. Here we used cotton which is a cellulose fibre and silk which is a protein fibre. For this technique and for natural dyeing, Alum mordant will bind the colour and make it light and washfast on protein fibres such as wool and silk. It is not usually as effective as a mordant for colouring cellulose fabrics such as cotton and linen but the addition of tannin (which occurs naturally in the leaves) will help to make the print permanent on the fabric.

Creating the Botanical Print with Leaves

For this experiment, the damp cotton fabric was laid out onto a sheet of plastic.

Leaves from the Cotinus Coggygria “Royal Purple” on Alum mordanted cotton fabric. Note that all the leaves are facing upwards. The underneath of the leaf will more readily leach colour than the smooth top side of the leaf. Turning some of them over will give a different result.

Alum mordanted silk fabric was placed over the leaves. This method allows you to produce two prints on two different types of fibre in one process – a great opportunity for experimentation and note taking.

A number of the leaves were beaten with a hammer to see what would happen.

Beat leaves with a hammer

The pretty shape of Lilac leaves – we would never have guessed that the colour would be such a vibrant yellow! Note that some of the leaves were turned over.

Liliac leaves on cotton fabric


Lilac leaves covered with silk fabric

A sheet of plastic was placed on top of the leaf sandwich and then carefully folded over before tightly rolling it around a length of hosepipe. It is usual to wrap the fabric around a wooden or plastic dowel; the hose was used because there wasn’t anything else to hand.

Rolling the fabric with the leaves inside

Botanical Eco Print ready for steaming

The hose proved to be quite effective! Its flexibility allowed the rolled fabric to be made into neat little parcels. The parcel on the left was bound with butchers string and the parcel on the right was bound tightly with a length of recycled plastic.

The final step was to wrap the parcel in a sheet of tin foil before steaming it to extract and set the colours from the leaves. Follow our instructions for Steam Fixing Acid Dyes as this will produce the desired result. This can be smelly and potentially release fumes. It is recommended to open windows and ventilate the room.

The Results!

The prints using Cotinus Coggygria leaves on silk (left) and cotton (right). Yellow with purply grey outlines on the silk and a full leaf print of purply grey on the cotton.

Botanical Prints rinsed and drying

Note how the leaf printed yellow on silk (below) with a purply grey halo. The image of the leaf indicated by the arrow is from one of the leaves that were beaten with the hammer, this obviously improves the process – the leaf print on the cotton was also better defined.

Leaf pounded with hammer before tying up

The Lilac leaf print on cotton (left) and silk (right). This stunning colour looks exceptionally good on the light reflective silk fabric.

More Experiments with Botanical Printing

A breakfast tea bag (tannin) and a Camomile (yellow) tea bag were infused in boiling water before adding to the Alum mordant solution. A dampened silk scarf was then soaked in the solution before using Busy Lizzie leaves (purple) and Lilac leaves to create the print. The teas have provided a subtle background colour for the print.

Explore the Fibrecrafts Natural Dyes to discover other colours for your fabrics. Madder and Logwood can be used to prepare fabric for a strong and contrasting background colour, while Oak Bark or Cutch can be teased to a bright orange when used with Titanium Oxalate mordant.