For the Delirus Mediaevalis Scientia Feriae (Mad Science Fair) event that was held this weekend, I put together a display on printing ink and linseed oil, as well as a demo on the printing press.
For the ink display, I had 5 glass vials, each containing a liquid and a small ball bearing. I had a vial for each of the following liquids: water, modern India ink, raw cold pressed linseed oil (called flaxseed oil in the USA), commercially available “boiled linseed oil” (available at most hardware stores), and commercially available artisans boiled linseed oil (stand oil). When you picked up a vial and turned it upside down, you could get a qualitative idea of the viscosity of the liquid by how long it took the ball bearing to fall.
Things I learned: no surprise, water and India ink have about the same viscosity. Commercial “boiled linseed oil” from a hardware store is actually just linseed oil with chemical driers added to it and has about the same viscosity as raw linseed oil. Artisan’s boiled linseed oil is very very viscous. The ball bearing took a long time to drop to the bottom of the vial.
The ink display at the Mad Science Fair, includes vials of water, India ink, raw linseed oil, commercial "boiled linseed oil", and stand oil (artisan's boiled linseed oil)
I also demo’d printing a woodblock on a hand press. I had made the press for Pennsic, and while it certainly isn’t period (it is built off of a bar clamp), the mechanics are period with top down pressure. I had a lot of fun teaching about printing in Europe and letting people get to print little images of a medieval tent copied from a period woodblock. Someday I would like to make a small demo press that is actually modeled off of a period press.
Setup for a printing press demo. People could come and print a small block with the image of a medieval tent taken from a period woodblock.