Their paint line was developed by founder Peter Marston for use in their greenhouses, after he found conventional paints were too toxic and didn't last long enough...
The Marston paint line is pricey (@ $50 a gallon), but not unusually so for paint of this quality.
First, they are healthy:
They are water-based, with little odour and are non-toxic, and they are already in line with the new directive for VOC levels for 2007 & 2010 making them safe and easier for those that use them, and to transport.
And second, they are rich in color with over 12 top quality pigments in each color (as opposed to the average 6 in a Benjamin Moore color, for example). In sum, they hold rich color and last longer than traditional oil and latex paints.
The only drawback (aside from price) is the color range, which, for many, will be too limited. Designed for use within the English country palette, the colors are beautiful, evocative of Martha Stewart (at her best) and very historic. You can see the full range here.
Paints are mixed at the Marston stores and can be shipped anywhere in the world.