The case opens to display the brushes while you're working. Each brush tucks into its own elastic holding strap. I like to drape the case over the left page of the sketchbook while I'm working. Turned inside out, the case can also set up on the ground like the letter A, with the cord holding it open at the desired angle. When it's closed up in travel mode, a magnet clasp secures it.
Here's the painting I did with those brushes, using gouache (opaque watercolor). I thoroughly documented the making of the painting on video, and it will be one segment of the next DVD/download called "Gouache in the Wild."
The brush set includes four rounds (sizes 2, 4, 6, and 8) and three flats (sizes 1/4", 1/2" and 3/4"). The combination of brush sizes gave me everything I needed, even for the fine details of the neon supports and wires. The close-up detail above is about an inch and a half square.
They're are all made of synthetic fibers, which is what you want for casein especially (the ammonia in casein is hard on brushes). The flats don't hold as much liquid as an equivalently sized sable brush. These are more chisels than mops. They have just the right amount of spring, and so far, they have held their points and edges.
You can get the Richeson Travel Brush Set from a variety of art suppliers, including Daniel Smith, Cheap Joe's, and Dick Blick.
The set of seven brushes, complete with their case, retail for $79.95, but on Amazon the set is discounted to $38, which is an amazing deal.