Travel Gouache Set
I decided to exclusively use gouache paints for my travel sketches in 2014. Gouache is amazing medium. It's really just an opaque form of watercolor, but it ends up having certain properties that make it ideal as a travel paint set. For example, watercolors lose their bright colors against the manila surface of Moleskine journals, but gouache retains its bright opaque qualities, and so even on Moleskine paper, the paints appear as bright as acrylic.
I found this Gouache travel set for twenty-one dollars. It has 24 pans, a tube of white, a built-in mixing pallete, and it folds together nicely into one solid brick. The gouache paints work perfectly with water pens.