Knowing how to make natural inks is a prepping skill that everyone should know. In the months or years after SHTF you are going to need to know how to make these ink pigments so that written communication still continues on. Also using natural surroundings and plants to create pigment, you can learn to make dyes for clothing and other needs. Here is one example of how to make ink. mind you there are hundreds of ways to do it, and veggies and herbs/flowers to use.
Instruction: put flower petals into a glass and cover it with warm water. Leave it for a few hours (I left mine over night).
After this time separate the liquid. (You can boil it for a while to get stronger color – optional.) Add strong alcohol in proportions 1 dose of alcohol to 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 colors were strong, but after a week the blue ink looked a bit faded. You can see how each color looks right after making them.