@prasad1970, where do you get iron sulfate??? I wonder if you used green tea, what color ink do you suppose that would would yield?
I have some green tea and will experiment

Indians make tea by boiling the tea leaves in milk and water and green tea is normally just infused in hot water. But will try both and tell you what happens. Iron sulfate is normally available with all Chemical Suppliers. Just ask them for Ferrous Sulphate FeSO
4.
I got it in a chemical supplier shop for schools here.
@prasad1970 that is absolutely amazing!! thanks for sharing the recipe!
Being unable to find iron sulfate, I tried the 100% natural recipe (raspberry + vineyard + salt).
This is the result.
Smell is not as good as a rose... believe me, you have to totally love nature and green-life to love this ink.
- I fear it's light-sensitive / will see how it changes after sometimes exposed to sunlight
But it's fun making it 
This is awesome

Yes, with some other fruits and veggies I have tried, the smell is ..... like you said "have to be a nature lover"

It is light sensitive, exposed to sunlight, it grows fungus after about 1 week.
But the fun involved and the lovely shades are amazing.
I have a friend who is into natural dyes. I tried making some inks with him and below are some results. This was done ages ago and I have not been able to experiment more on it.
The shades were quite light and the names I have mentioned are in Hindi (Indian language)

Anar = Pomegranate (used the dried powdered skin)
Haldi = Turmeric powder
Katta = this is from a tree bark (Acacia Catechu Powder) mainly used in India as hair dyes like Henna
Harda and Sappan = again powdered barks of different trees.
IN textile dyeing, they dip the cloth or yarn more than once into the dye to get a richer, darker shade. I haven't figured out how to make it more saturated yet.
Been too busy practising "ovals"
