Natural Silk Dyes – Woad Blue (Isatis tinctoria)

Woad plant is blue green leaves with yellow flowers, behind the tomato leaves.

Two samples of successful silk dying with small harvested amount of woad leaves. First dye session: two pale blue results.: Left: 2nd weaker soak, pale blue. Right: 1st soak, pale pastel blue.

Woad Dye Bath Process – 1st Session

Boil woad leaves – liquid is sherry coloured – Images (2, 2a, 2b) Add soda crystals until alkalinity reaches 9 – Images (3, 3a, 3b) – Whisk liquid until froth forms. Takes 10-15 mins. Liquid can also be poured from one pan to another, making bubbles. Images (4, 4a, 4b, 4c) Froth is achieved at (5)

Heat dye bath to 50 deg again. Set aside 20 mins. Add desert spoon sodium dithionite to remove oxygen. Add enough until dye bath turns limey green. Place silk in liquid carefully without creating air bubbles. Submerge. Leave for 20 mins. Image (6) (it starts to work soon if some fabric is left out in the air (see 2nd Session below).

Remove fabric and rest. Watch it turn blue in air. (mine went turquoise on ahimsa cream silk using pond water) – Images (7, 8) Rinse out when colour as dark as will go, hang out to dry. (9)

Woad Dye bath process – 2nd Session

Woad colouring occurs quickly after exposure to air, following soak in woad leaf dye bath, which has had oxygen removed by sodium dithionite.

Woad Dye Bath Preparation

Woad leaves are cut up and soaked before boiling and simmering for an hour. Remove leaves, then dye bath needs soda crystals, before whisking for 10 mins until froth forms. Woad dye bath is ready when there is a pale blue or (in this case) pale green froth. Reheat dye bath to 50 deg. then add spoon of sodium dithionite to remove oxygen. The water goes limey green.

Turquoise appears when all silk is added to air after 10 mins soak

The dye was uneven, so I re-heated the dye bath again, added the same chemical again, and replaced the fabric, but the magic had gone, the blue disappeared! The result was a pale grey blue, which looked dark in the rinse sink, but dried quite pale.

See more and others’ dye procedures on my Natural Plant Dye Pinterest Board.

To be continued…..