Having the good fortune to work close to a 44-acre nature preserve, I go for a hike nearly every day. I bought a Moleskine sketchbook (3.5x5.5 inches) that fits nicely in my pocket, along with a few pens, so that I could do quick sketches. After doing a few of those, I decided that I really needed a water brush so I could put in washes. After a week of doing of ink and wash, I was really feeling the need for color and so started looking for a small paint kit that would fit in my pocket. I did consider making one out of a candy tin, but the collapsible Sakura water brush sold me on the small Sakura paintbox. I carry a brown and a black Sakura pen (waterproof ink), and a black micro Uniball (not waterproof) for when I want to get a gray wash out of a line.
The Water Brush
The Water brush is a great Japanese innovation - a brush attached to a hollow handle that you fill with water. Not all water brushes are created equal. I got a set of Aqua-flows, and they are not terrific, the water doesn't flow very evenly; however, that is the only brand I've found that makes a flat brush--all the others are rounds. Also Aqua-flow's smallest round is not very small. The Sakura Koi is excellent--nice bristles and good flow, and has the advantage of a plug for the barrel, so you can fill it with water, but carry it broken down in your paint box. I have read good reviews of the Yasumoto Niji water brush, and will buy one of those to try. Brushes run around $6 to $9, depending on what you buy and where. Ok, tried one of these--they do have a tiny brush--manufacturer seems to be the same as that of Aquaflow. I like the Sakura Koi best.
The Paint Box
So, I bought the Sakura Koi, Pocket Field Sketch Box, which has twleve colors, comes with a Sakura Koi water brush (very nice!) and a small sponge to wipe the brush on to clean it between colors. The box measures 3.5x4.5x 7/8 inches and has plenty of mixing room in the lid. The paint picks right up with a wet brush, so there is no scrubbing at the paint to get color on your brush. The only snag was that there is nowhere to put the plug once the brush is assembled, so I used a piece of poly thread to attach the plug to the box. I wanted a few additional colors, and two half-pans fit in nicely. When the sakura paint runs out, I plan to fill the box with half pans; with the plastic paint holder removed, 18 half-pans fit in the box. The 12-pan box (Sakura makes 18- and 24-pan boxes, but they are bigger) runs between $17 and $25.
The Moleskine Notebook
I am totally in love with these notebooks--as any lover of books would be. They are beautifully made, with and elastic band to hold it closed and a pocket on the inside back cover. The sketch book has 84 pages (42 sheets) and vertically formatted. The paper is quite slick. To get the paper to take watercolor, I wiped down the pages with a wet sponge to remove some of the sizing and then blotted them with paper towel. I did about a signature at a time. The watercolor sketch book has 200 mgs watercolor paper and 60 pages (30 sheets) and is horizontally formatted. The small notebooks run from $12 to $15. I think that these are reasonably priced--it takes a while to fill them. Matisse, Van Gogh, and Hemingway are a few past Moleskine lovers, so you will be in good (and inspired) company.
Putting Tube Paint in Pans
I have been filling my plein air watercolor pallette with tube paint for a while now, and one problem is the pigments drying out--particularly the earth pigments and cerulean blue. I did notice that back when I had gum arabic in the water in my spray bottle, the paint didn't dry out. So I put a tad in the two half-pans in the Koi box before adding paint and mixed with a toothpick. The are staying quite moist. Also read that glycerine and honey are used to make semi-moist pans. So I thought I would try that. Right now I have some soupy watercolor and gouache that have both honey and gum arabic. However, I did do one palette that has worked well (so far)--paint is semi-moist--I mixed a teaspoon of honey with a teaspoon of water and put a drop of that in the bottom of each pan in the palette. For oil palettes, I have read--but not yet tried--that putting a few drops of oil of clove in the palette box before closing will keep paint fresh.
I put together the kit because I wanted something that fit in my pocket and that involved about zero setup and breakdown time. But then...this is so much fun to use, that on the weekends, when I don't go to the park, I find myself doing paintings of things around the house (like the cats) when I have a few minutes to kill. This makes doing "a painting a day" really easy. I even do paintings when I'm in bed.