After two days of solar soaking in their jars on a sunny windowsill, the Red Cabbage and strips of alum-acetate mordanted silk organza looked like this:
Left, water only; centre, water and acid/vinegar; right, water and alkali/ammonia (water, 250 ml; acid and alkali, 25% each)
Today, three days later, the solutions have changed colour dramatically, especially the green ammonia jar. Time to remove the silk.
Water only: blue
Vinegar and water: lavender-purple
Ammonia and water: almost no change, just a slight greenish tinge to the white silk, not detectable in my photo.
Conclusion here: Pre mordanting silk organza with alum acetate fixes Red Cabbage colour in solar dyeing conditions. But for how long??? Hmm. TBD. And note that NO dye run off (crocking) took place during rinsing.
Note that my previous Kinder Chem experiment with RC used white cotton yarn, with Bulk Barn alum mordant in the jar. Dye results were pale wimpy blues plus no change in the ammonia jar.
Next Kinder Chem steps:
1. Eco bundling the solar-soaked cabbage. Cabbage Rolls Ta Da.
2. Exposing the silk to sun light to test light fastness
Next post: More eco printing for the chuppah.
Plus I am going to add a blog page listing eco print and stitch artists out there. It would be a nice community resource to have!
Finally, for real dye chemists, consult work by Dr. Paula Burch (online) and Dr. Dominique Cardon (in print). See links in this blog.