The best way to use acrylics in high temperatures, wind, and low humidity . . . is to switch to oils.
If you’re like me, however, and are habituated to the quick drying time of acrylics, then you can modify your approach to very dry conditions by using Acrylic Glazing Medium rather than water when you dip your brush. This will give you extra seconds before the paint dries.
Gel retarder is made for these circumstances but has to be squeezed onto the palette and a tiny bit added and carefully mixed into every color you use. It’s time consuming and can result in slower or faster drying times depending on the mix.
The extra action makes painting less direct, takes longer, and can put you off your stride.
I much prefer using glazing medium to using gel retarder because I constantly wet my brush and this system relies on that habit.
Although Open acrylics were developed to overcome the problem of rapid drying, the paint may feel dry but not be fully dry underneath. This can cause the surface to pull up long after it is dry to the touch.
For me this takes away any possible advantage and leaves me with a medium I don’t trust.
“Last Light, Indian Peak,” painted near Borrego Springs, California. Located in the Sonoran Desert, the hottest desert in North America.