Calverts uses 100% vegetable oil based inks, with low levels of additives and metallic drying accelerators such as cobalt.
The oils are mainly soy (from soya), or linseed. Industrial soy oil is a commodity traded on world markets, and is generally blended from more than one source. This means that it almost certainly contains transgenic (genetically modified) soya. 90% of US soy production is GM, and the US government has successfully lobbied the World Trade Organisation (WTO) against the labelling of GM soya, making it almost impossible for buyers to ‘discriminate’ against their product.
On balance, we still firmly believe that vegetable oil based inks are preferable to mineral (petrochemical) or mixed alternatives.