Making Ink from Oak Galls

Four greeting cards with coloured ink blobs
Greeting cards made with iron and oak gall ink

Iron gall ink is a black ink made from oak galls, iron salts, and gum Arabic. Iron gall ink has been in use for thousands of years. It is considered permanent, and has been used for legal documents until recently. Oak galls are wasp incubation pods found on oak trees.

Iron gall ink is also known as oak gall ink; however, technically you should include the word “iron” if it contains iron.  (I use both interchangeably, but am trying to be better.)

Here's the content we've got about making ink from oak galls: