Back in August I bought a pocket palette by Expeditionary Art. http://expeditionaryart.com/shop/#art-toolkit.
I really liked the size and it came with 14 empty palette pans that I could fill up with my favorite watercolor paint. Well I've been using this pocket palette daily that I thought about buying another pocket palette for my gouache, but I wasn't sure I wanted to spend another $28.00 for another one. Two weeks ago I happened to visit expeditionary art shop and noticed that they were offering jumbo size palette pans, so I bought 15 jumbo palette pans thinking I could switch pans with different colors.
Last week when I was in Dick Blick I happened to notice that they carried these empty business size card cases that were exactly like the pocket palette that I had bought from Expeditionary Art, so I bought two of them for $5.99 each.
With a small adjustment I was in business. I had too add magnetic tape to the bottom of the palette pans so they would stay in place and not pop out when I opened the case. The flap of the case is already painted with white enamel paint and the lid has a ruler on the top.
With the 2nd case I plan to add more watercolors that I use on occasion. I'm always happy when resourceful.