Iron Gall Ink: A Quick and Easy Method (UH0022)

2g gum arabic crystals
10g of oak galls
2.5g iron sulfate

1. Dissolve the gum arabic in 29 ml of water, making a light, sticky solution; set aside.
2. Crush two oak galls with a hammer. Place them in a litre beaker and cover with 75ml of water overnight until they create a brown-colored solution. Filter out the solids.
3. Dissolve two teaspoons of iron sulfate in 45ml of water; set aside. The blue green crystals will turn to a muddy brown color as they dissolve into solution.
4. Mix the gall and sulfate solutions; it should produce a dark blue-black ink.
5. Add the gum arabic solution to the ink to give it some thickness.

Shape your quill and write!

We have news! Since this filming, our team of 11 researchers worked together to read an unopened letter virtually – the words and the folds – for the first time, without ever breaking its seal. What does the letter say? Head to our website https://www.letterlocking.org to learn all the details and celebrate the launch of letterlocking! Read our findings in our Nature Communications article, https://doi.org/10.1038/s41467-021-21.... Visit our Dataverse, our open repository for data collected for this project: https://dataverse.harvard.edu/dataver....

Produced by MIT Video Production. Directed by Jana Dambrogio, Dr Nadine Akkerman, and Joe McMasters. Funded by the Netherlands Organization for Scientific Research (NWO), VENI-project “Female Spies," and Massachusetts Institute of Technology Libraries. Many thanks to Ayako Letizia for preparing and demonstrating how to make and write with the iron gall ink and to Phoebe Dent Weil, Birgit Reissland, and Rich Spelker for their expertise and assistance in providing historic ink recipes.

Citation information: Authors: Jana Dambrogio, Ayako Letizia, Nadine Akkerman, and the Unlocking History Research Group. Title:"Iron Gall Ink: A Quick and Easy Method”, Letterlocking Instructional Videos. Unlocking History number 0022/Letterlocking Unique Video number: 022. Date filmed: September 2014. Duration: 4:45. Date posted: December 2014. Video URL: [Insert URL]. Date accessed: [Date].

Copyright 2014–present. Jana Dambrogio, Nadine Akkerman, the Unlocking History Research Group, and the Massachusetts Institute of Technology (MIT). All rights reserved. The following copyrighted material is made available under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License https://creativecommons.org/licenses/.... Contact the MIT Technology Licensing Office for any other licensing inquiries.

Interested in spies and their secrets? See also Nadine Akkerman, Invisible Agents: Women and Espionage in Seventeenth-Century Britain (Oxford: University of Oxford Press, 2018).

NB: Letterlock responsibly. Be mindful of open flames or hot tools.

To find out more about letterlocking, visit http://letterlocking.org and follow us on social media @letterlocking.

Follow our collaborators on Twitter @misswalsingham @NWOHumanities @MITLIbraries @LeidenHum

Youtube URL: http://bit.ly/IronGallInk or    • Iron Gall Ink: A Quick and Easy Method (UH...