EPISODE 21: THE SCIENCE OF INK WITH NICOLE SHARP, OF FYFLUIDDYNAMICS

Months ago, a viewer asked for an in-depth discussion of how fountain pen ink works. I responded that I was game, but I had to find the right person to talk to. After a several-month search, I met Nicole Sharp of @fyfluiddynamics at the 2025 Commonwealth Pen Show. Nicole graciously agreed to come on talk about the science and physics of fountain pen ink. We go deep, talking about how inks are formulated, the physics in your pen and how ink gets out onto the paper. Nicole also explains her own ink related research. This episode has everything you wanted to know but were afraid to ask about the lifeblood of our pens: the ink. You can learn more about Nicole and fluid dynamics at her website https://fyfluiddynamics.com and through her channel at https://www.youtube.com/@fyfluiddynamics 00:00 Intro 01:38 What is in Ink? 02:03 Viscosity and Ink 04:59 Shimmer Ink Ingredients 05:57 Surface Tension and Ink 08:04 How Ink Moves Through a Fountain Pen 13:44 How Ink Gets Into the Paper and Sheening Ink Explained 20:39 All About Feeds 25:55 Surfactants Like Vaness's White Lightning to Increase Flow 27:22 Wet v. Dry Inks: Science Explains the Difference 37:00 Feathering Ink Explained 38:37 Oils and Ink 40:02 What is in Chroma Shading and Sheening Inks 43:26 Outro and Thank You Thank you to ‪@Yoseka‬ ‪@appelboompennen‬ ‪@stiloestile04‬ and ‪@CBSNewYork‬ Footage from ‪@CBSNewYork‬ is as seen in https://www.youtube.com/watch?v=cy2jOghaAr0 _______________________________________________________________________ Uncapped is created by Joshua Lax, proprietor of the J.J. Lax Pen Co., which specializes in nib repairs and modifications. Find out more at: jjlaxpenco.com Instagram: @jjlaxpenco Reddit: u/jjlaxpenco