A little fun with the Red Cabbage dye I cooked up for one of my recent silk-wool panels.
The dye bath: One half of a red cabbage, chopped and simmered for an hour in my aluminum (Pot As Mordant) turkey roaster gave this deep purple dye. In that I simmered a silk-wool bundle which gave a soft lavender-grey.
o each jar was added 1 teaspoon (5 ml) of alum acetate powder (mordant) and a few bits of boiled cabbage:
Lovely blues! Now to modify the colours with additions of acid and alkali:
On the left: Just Red Cabbage dye. Centre: 1 teaspoon cider vinergar (5% acid) Right: 1 teaspoon household ammonia. The acid pushes the blue cabbage dye towards reds while the alkali pushes it towards greens.
Set the jars on a sunny windowledge. Dropped into each jar a skein of white cotton embroidery thread (vintage Beldings), not previously mordanted or wetted (but alum was added to the jar) . Left to sit in the sun inside the house for a few hours (no cooking).
The skeins are somewhat different in shade of blue. The pure Red Cabbage dye on the left gave a deeper lavender shade, while the acid changed the colour slightly to more bluish. The suprise here is the ammonia modifier: it drove the green into the Red Cabbage (which was purple at the start) to make it dark green; and left the white cotton skein white in the end.
(That is sort of how things work with safflower dyes -see previous post on the process of obtaining red on silk from a yellow safflower dye solution by messing with acid-alkali levels).
Here the white cotton skein “surrogate” collected the green colour from the alkali solution and discharged back into the cabbage, dyeing it green. Wow. Not getting a PhD in Chemistry any time soon.
Next post: Sewing up those eco prints for the show! Hemming torture. Any relief out there?