Unless I'm painting my house, my colored butyrate needs are typically small. Colors cover well, so one or two sprayed coats is all I need on a new plane. That would typically be about 4 oz.
Therefore, I buy colors in pints, or sometimes in 4 oz. bottles. All this is Brodak...because it is readily available and is also a pretty good product.
I use much more clear butyrate, which I get from Aircraft Spruce, 2 gallons per order. Thinner comes from a local industrial paint supplier as PPG Acrylic Lacquer thinner.
Floyd