I love working plein air (a.k.a. outside). I started in art school and just loved getting outside on a beautiful day. With plein air, it's interesting how the artist feels in the environment impacts the work. If it's cold and windy the piece will reflect that tension in the strokes.
Here's my set up for plein air painting. I prefer oils...of course charcoal or watercolor is even easier!
Here are some of my travel specific supplies:
2 tiny brush washers: one for baby oil for on-the-go brush washing and the other for turpenoid.
canvas pins: use these to store two paintings face to face. then mount them on the easel for easy travel back home.
It's been soooo long since I've painted. I'm really looking forward to getting outside to make some art!