Wild Berries As Stain:

[Rodney]

I just took a quick photo of some wild berries and the plant section from our farm. I squashed up one of the little purple berries from the photo and it made a nice index finger print onto the paper which may not be all that visible from the camera.
This is a wicked purple stain that does not wash off very easily and I understand these berries are poison, but certain insect eat the plant anyway, thus nothing will eat this insect as I understand it, so life continues.
Anyone tried this type of berry as a stain or possible others? I do not have the name of this plant species at this time, but I still have a purple index finger.
Rodney