Thin films

Just a small homework assignment–turned–painting experiment–turned short “film,” investigating the height profile of a thin film draining by gravity on a vertical sheet. The shifting color lets us infer film thickness, which we’re interested in tracking over time. It’s especially satisfying in the yellow paint, where the masstones range from dark ochre to brilliant yellow when the white substrate shows through from the support. The paint is Lascaux Aquacryl “Transoxide Yellow”, or PY42 in a proprietary acrylic dispersion, per the manufacturer. This synthetic yellow iron oxide, developed in the mid-1900s, was a breakthrough due to its alluring transparency. Natural iron oxides comprise some of the oldest-known paints but are typically opaque and so do not produce such distinct gradations as this synthetic version.

To see more yellow paint with a strong masstone and transparency — this time PY83 in oil — see the yellow “brushstroke” painting here.

I hope to add some additional notes and plots here soon—spoiler alert: the profile takes the shape of a square root. In the meantime, please enjoy the movie.