Eco-Prints 10/04/2021 10/04/2021 / Art, eco-prints / nature young leaves using a mono-printing technique called eco-print. Where the paper is treated with alum (release the natural dye colors), the leaves, flowers, etc. are flattened on top, then another treatment of vinegar water (help set the dye) or iron water (gives the rust color, as in the photo above). the paper and plants are built in layers and steamed, or ironed individually (using heat and steam to release the natural colors. this photo is several lettuce leaves steamed (with iron ) and just alum water and vinegar water to release natural color.