A vibrant Sap Green ink was obtained by combining two plant-based pigments - Natural Indigo (Indigofera Tinctorum) and Buckthorn seed (Rhamnus Petiolaris Boiss) - with bio-based binding agents to screenprint on cotton and linen fabric.

Screen printed with handmade plant-based ink on eco-friendly linen cotton fabric.

The process starts with sourcing or foraging the plant material, Buckthorn, and Indigo. Buckthorn seeds can be harvested in the late summer through autumn while Indigo leaves are best to forage before the blossoms open. One of the most important rules to respectfully forage plant material is to look at the abundance and never collect more than two handfuls or work with sustainable and fair-trade producers. While Buckthorn seeds are dried and ground for yellows, Indigo leaves are used to extract the blue pigment. The two powder pigments are then mixed on mortar and pestle together with water and left to simmer to reach the Sap Green hue. After around an hour, alum is added to modify the pH of the solution and left on low heat for another half hour. It follows the addition of a combination of binding agents to reach the viscosity for screen-printing and turning the dye into an ink. Thyme oil helps to naturally preserve the ink. Before screen printing with it, the textile is scoured, mordanted with a tannin solution made with oak galls, and secondly mordanted with alum. These allow the ink to be absorbed by the fiber and prevents it from being washed away when in contact with water.

Ingredients: Natural Indigo (Indigofera Tinctorum), Buckthorn seed (Rhamnus Petiolaris Boiss), Agar agar (Eucheuma), Guar gum (Cyamopsis tetragonoloba), Arabic gum (Acacia senegal), Alum (Potassium alum).

This material is included in the Future Materials Bank's archive and in the Materials Design Map