Chrozophora tinctoria is a rather frequent plant in some localities in Malta especially those close to arable land. It is a summer flowering plant of the Euphorbia family.
The tiny flowers (males and females separated on same plant) are inconspicuous, but the fruit has a rather peculiar shape - 3 spherical locules joined side by side.
The species epithet - 'tinctoria' simply means a dye or ink, since the plant gives a bluish dye. As far as in Medevial times, this plant was much used to derive ink.
You can easily extract your own ink at home from this plant, using the fruit. Take a dozen or two mature fruit (unripe = green, mature = dark green, very ripe = nearly black) and add approx. as much volume of surgical spirit (or ideally ethanol) and same amount of boiling water.
Shake or mix constantly and you would see instantly a dark blue dye leaking out. Later, it becomes so concentrated that the liquid eventually turns black!
Pour the solution, or better to say, the tinture in an evaporating basin, cover and leave for few hours in the sun to evaporate and hence concentrate. Finally put some of the black liquid in a ink-refill pen, and you have some ink as used in medivial times.
If you acidify the solution with few drops of lemon or vinegear, you would have a different colour!
More info about this plant:
- Ink from Chrozophora tinctoria
- Chrozophora_ink.JPG (90.27 KiB) Viewed 22710 times
It started out a beautiful aqua color, then shifted fairly quickly to purple. I expected this, but didn't expect the following: overnight the color shifted all the way to maroon. I had thought that I would have to add something acidic to force the change to red. On rereading my sources I realize the opposite: if I wished the color to remain purple I'd have to add something alkaline. They used urine for this 600 years ago but I have some washing soda I'll try instead.
Just for fun I went through with my original plan and added a few drops of vinegar, 5% acid. The color of the liquid is now a fairly bright rose. Quite happy with it, though I'll be happier once I can obtain all three colors. I have a very small amount to make a lake pigment, but I'm considering an attempt. Has anyone tried this?
What solvent did you use for extracting the dye? Did you boil ?
I also messed with acid/alkali condition and got some great colour, and remeber that unlike several dye extracts, the red/mauve was achieved in alkaline conditions. Makes a good pH indicator!
I don't know but I thik the dye gets easily oxidised so keep your solution closed (or make some research on this personal observation)
I'm surprised by the alkaline for red, I had thought it was the other way around. Can't wait to play with some more of this stuff - it's quite a plant. Next time I will definitely experiment with the oxidation, thanks!