I've read about natural dyeing in an old book about properties of herbs and wanted to try with poppies, but foud very few. It was after poppy season. As I had only a handful of the most important ingredient I had to do something different and found the solution in the same book!
Instruction: put flower petals into a glass and cover it with warm water. Leave for a few hours (I leaved mine for a night).
After this time separate the liquid. (You can boil it for a while to get stronger colour - optional.) Add strong alcohol in proportions 1 dose of alc:4 dozes of extract.
Ink is ready to use!
I made three inks - out of poppy, kingcup and blue sweet pea. At the beginning all three colours were strong, but after a week blue ink looked like faded. You can see how each colour looks straight after making below. Poppy ink has exactly the poppy colour, lovely!
To sum up, natural inks are worth making. If you like flowers because of their variety of colours you should try this for sure.
Have a beautiful day,
EDIT: A lot of people visit this post and I got asked in the comments about flowers that can be used etc. HERE is a long list you can use for natural dye or making this ink. These flowers are used in dying fabrics, so the colour shouldn't fade or so on. Now, almost a year after making my inks, I still have one of them (yellow), and the colour is as strong as it was at the beginning.