Are water-based inks Biodegradable?

First of all, it is more correct to speak of compostability (as stated in EN 13432) rather than biodegradability which is a generic concept.
Commonly used Water-based flexographic inks made with over 50% water and inactive components, cannot be defined compostable since they contain a high percentage (around 30%) of organic substances derived from synthesis, characterized by a very slow biodegradability.
For what has already been said, La Sorgente proposes the Hydromat-B (463 series) and Ecomat-B (163 series) products, respectively, water-based and solvent-based inks that allow printing on compostable substrates without invalidating the compostability of the final packaging.
The Hydromat-B and Ecomat-B products are inert, tested and certified by Vinçotte which do not compromise the compostability of the final article (as stated in EN13432).