Preparing cellulose Fibres for ecoprinting

Eco printed fabric with the addition of block prints using natural dyes

There are shortcut methods but the results can be variable. This method will insure the best possible results from steaming bundles for eco printing - I will discuss bundling in another post. Because we are using chemicals it is a good idea to have a set of measures and pots etc to use just for eco dying. I pick mine up very cheaply for time to time at thrift stores.

Scouring

Scouring is the first process. This removes all the fabric finish so it doesn’t interfere with the printing process. Even vintage linens may have residual soap particles that need to be removed. Weigh your fabric dry and record this weight. For every 1000gms of fabric you will need 80 gms of soda ash (8% of weight). soda ash is the ph modifier used in spas and swimming pools so this is the most economical way to purchase it. Small packets can be purchased from craft stores but it is much more expensive to purchase that way. You will also need about 1 tsp of a ph neutral washing powder such as Joy, Fairy or Dawn. Some people recommend using synthrapol but this can be difficult to obtain and has some carcinogenic properties so I prefer to stay away from it.. Three quarters fill a large pot with water. The pot needs to be large enough to accommodate the fabric and easily move it around in the water.

Dissolve the soda ash in boiling water and add to the pot

Add the detergent

Add the fabric and bring to the boil. simmer for 1 -2 hours. You will be shocked at how much the water discolours.

Remove and rinse well before applying mordant or you can dry and store for later use. Make sure you label stored fabric or you will find you don’t remember if this was just scoured or mordanted. Believe me I am speaking from experience.

The water is fine to put down the drain.

Mordanting - the tannin step

There are various tannins available. Some add a slight colour to the fabric but all will add impetus to the cellulose fibre. The tannin increases the ability of the mordant to “bite” into the fabric so the print is adhered. Mordant comes from the French word to bite. Using your dry weight of fabric (WOF) you will need 10% of the weight in grams. Oak gall tannin does not colour the fabric but is difficult to obtain in New Zealand as the oak gall is made by a wasp which we do not have in this country. I tend to use myrobalan as it does not leave much colour disturbance.

The tannin powder needs to be mixed slowly to a past and added to hot water - ideally below 140degrees to stop the tannin darkening. Add the mixture to a large pot of water and add the fabric. The fabric needs to be well wetted before adding to the pot. Try to not allow pockets of ait or folds as you add the water so that all fibres are subjected to the tannin.. Stirr

Stir again after 30 minutes. After an hour you can remove the fabric and squeeze out excess liquid. You can dry and label or go to the next phase.

Mordanting the fabric

This is the final step in preparation of cellulose fibres. Again using weight of dry fabric to calculate proportions add 12% potassium aluminium sulphate and 1.5 % soda ash. this sometimes fizzes in the pot so be careful when you add these two together. Add the wet fabric and Bring to a simmering point. Simmer for one hour. Remove, rinse and dry or continue to use for natural dying processes

Note This process is only for cellulose fibres - those created from plant materials - cotton, linen, banboo, ramie etc.

It all seems a bit of a process but i tend to prepare a batch of fabric and then store that for use as I am eco dying - hence the importance of labelling which stage of the process you have stored the fabric as you won’t be able to tell from the fabric

Commercially printed white on white cotton fabric gives some interesting effects.

By following this process your prints will be permanent and able to be laundered without undue fading.