Hello there! Here is my latest natural dye test! This post only contains one dye test opposed to the usual three, but that is because this test was very specific for a shirt. And I knew the goal was blue. It had to result in blue (oops spoilers!) no if, ands or buts. I used black hollyhocks to achieve it and it worked with a little bit of help.
When researching what to use for a blue dye I came across the black hollyhock recipe (and recipe is a term used loosely here) in Rebecca Burgess’s Harvesting Colour book. I followed the recipe roughly by pre-mordanting my fabric in alum, soaking the dried blooms in water overnight before adding heat, etc. Although admittedly I didn’t weight the flowers to ensure a 2:1 ratio of flowers to fabric. I just eyeballed it.
Anyways After following all the instructions up until taking the pot off the burner I had to improvise. I tossed in a snippet of the silk-cotton blend I always use and it came out more of a hydrangea purple colour… Not what I wanted so I did what I always do when things don’t go my way in natural dyeing… Playing with the pH.
The gist of this is adding either a base (I use baking soda) or an acid (I use white vinegar) to the dye bath to see which colour the dye turns to. My rule of thumb is that acid pushes more towards the warm/pink side of the colour spectrum and bases push towards the cool/blue/green side of the spectrum and that carried over to my hollyhock dye. I started by putting some dye into a glass and adding a very small sprinkle of baking soda to the glass to see what happens by holding it up to the light and adding another scrap of fabric. I discovered that the smallest bit of baking soda worked well with my dye bath (I used rain water so the waters pH was softer than our normal tap water. So I recommend to keep that in mind when you go to try this dye bath). I got the perfect desired blue doing this so I was very happy.
My blue was less turquoise and vivid than depicted in Burgess’s book. I think this is because I didn’t use wool for one thing. I used a silk-cotton blend. And I didn’t soak my fabric in the dye bath for hours like the book instructed. I soaked my fabric for 15 minutes max. What can I say, I’m impatient and I like pale blue. Especially that blue that isn’t achieved from poisonous monkshood…
So that is my experience with black hollyhock dye. I love it and I will be growing so many hollyhocks in the future. They are also one of my favourite flowers so it is a double win!
I hope you enjoyed this,