Can you help me paint someone who’s sweating from being nervous? Amanda Bolton, US
If you look at a close-up of a photo of a drop of sweat on someone’s face, you’ll see that it’s just a tiny rounded surface reflecting the environment, much like a Christmas ornament. The top half will generally reflect the sky or light source, and the bottom half reflects the ground plane and objects. The surfaces that come around and meet the skin will reflect the skin, and the sweat’s refractive properties will make those edges appear darker. Often the surface tension against the skin texture will cause the sweat droplets to take on irregular, jagged shapes, but they still follow those principles of reflection and refraction. Sometimes, if the droplet is running down, the reflected highlight will fade up into the skin colour, and the drop might also cast a slight shadow beneath it.
In Photoshop, start with some dark irregular blotches and then fill in the reflected highlights and ground colours, adjusting Levels and Opacity as required. Keep the large overall skin highlights on your character very glossy; the skin is wet, after all. It’s going to look weird at first, but it’ll come together once you start adding Transparency to the droplets. Vary the size of the drops and increase some of the highlights, to suggest the drops are running down their forehead.
The key to painting sweat droplets is to not
overdo it and try to break up the uniformity. Make sure those skin highlights are glossy.
Anatomy of a droplet. It’s really like any other rounded, reflective surface – just smaller and semi-transparent. The sky and ground are both reflected.