Humidity is often high along the imaginary circular line which is the Tropic of Capricorn . As I write it is 86% humidity in Campinas, Brazil. In Phoenix, AZ, where I was a week ago humidity is just 27%. Why should I notice or care about the difference?
I notice and care because the paper I paint on, that being Fluid 300 140# hot press, behaves much differently between locations. Here in Campinas it retains water longer and seems to diffuse into smaller, finer capillaries. Also, the pigment stays workable longer because it dries slower. The paper feels a bit moist to the touch even when ‘dry’ and this makes the colors appear brighter than in, say, Arizona, USA. Perhaps the paint will dry and lighten when back in the US but for now I’m thrilled with the look of higher humidity.
As for the more visible capillary diffusion, that effect will remain in drier climates, I think. I like the delicacy of it. Here are two examples of the difference in pigment diffusion as well as yesterday’s painting, a study of a conifer branch and cone of a variety I’ve never seen before.
Diffusion of pigment at low humidity
Diffusion of pigment at high humidity
Conifer, 8 x 8″, 140# hot press watercolor paper