I bought the following items (I went for inexpensive here, so feel free to go all out – but these worked perfectly fine.)
(1) A Masterson acrylic palette (12″ x 18″ or 30 x 46 cm) with airtight lid. I took out all the insides (sponges, etc) and just used the bottom as a palette. I followed directions and put Vaseline around the lid edges. It kept the paints wet for days. I even left globs of paint on the palette in between sessions, and placed the palette vertically in my back pack, and the paint did not run. I attached 4 small 1 oz. plastic containers with lids (the cheap kind you get from restaurant supply stores) on the inside along one side of the palette with masking tape. I labeled each one as follows: water, thinner, medium, gel.
(2) An easel. I bought a lightweight portable very simple metal easel. The only drawback to this one is that it only works well with thick (1” depth) canvases. To remedy that, I bought one masonite cradled panel that was 1 ½” thick. I used this as a backing board, and could tape paper or cardboard surfaces to this.
(3) A folding umbrella. My umbrella (not pictured here) folds compactly and I keep it in the zipper pocket of my folding chair.
(4) A folding chair with carrying strap. The chair has zipper pockets to hold important items like sunglasses, tissues, drinking water bottle.
(5) A medium to large size comfortable back pack. This was big enough to place the Masterson palette inside. I also put the following items inside the pack: apron, camera, small container with a bar of soap (to wash brushes), paper towels, masking tape, some brushes and a palette knife in a fabric brush carrier, a baggie of paints (I kept my colors to a minimum of 10 paint tubes), a baggie with Open Medium, Open Thinner, Open Gel. A small fine spray bottle with Open Thinner inside. An 8 oz empty jar and lid for rinsing brushes while I work. A 12 oz container of water to refill the brush rinse jar, several small plastic grocery bags for trash (I tied them onto my easel hooks while working for an easy to reach trash can).
(6) Painting surfaces. As I mentioned earlier, I used canvases and panels that had a depth of 1” or 1 ½”. I also used one of those panels as a backing board for inexpensive surfaces like paper. I painted a bright red color on all my painting surfaces before I left. This was very handy – to have a medium value and bright color already on there.
(7) Other items good to have: a hat for sun or hat for cold weather, (also if it is cold – ski liners or gloves you can paint with), lunch and/or snacks, a watch.
I was able to hike about half a mile carrying all this stuff, before I realized the view looked fine, and if I kept walking I might get too tired to paint. I had on the backpack, with my chair strap on my shoulder, and carried in my hands my painting surface and easel. I set up in the shade (which kept my paints wet even longer and was easier to see colors and what I was painting). I put a few folded paper towels on my lap, then the Masterson Palette on top with the paper towels still accessible in front of it. I put all the brushes I wanted to use at first in the empty 8 oz container, filled it halfway with water. Then filled the small 1 oz containers with each of their fluids: water, thinner, medium, gel (I didn’t actually use the gel – so next time I might just skip it). I squeezed all my paint colors out, going from light to dark along the outside circle of the palette, leaving room in the center to mix.
One day it was humid and slightly drizzly, so I painted under a porch. The paints stayed wet all day. The next day it was very hot and dry, and the paints stayed wet for my whole painting session, but did get a bit tacky (still usable, though) after an hour or so.
After painting for awhile, the areas with paint on the canvas dried to the touch, so I could layer paint on top without a gooey mess. However, if I wanted my second layer to blend into the first, all I had to do was to place some Open Medium on top of the dried area and let it sit for a minute. Then the layer got usable again. I could do this for up to about 24 hours.