Tannins, Ferrous Sulphate, and using an Iron Blanket.
Botanical Printing on Paper – Franki Kohler
Wool - Tribulations of Hand Spinning and Herbal Dyeing: Making Leaf Contact Prints with an Iron Blanket
DIY Ecoprint Iron Blanket. Thanks a lot to Catharine Ellis for the mordant recipe of Concentrated Aluminum Acetate., By Aura Guignard
LEAF ECO-PRINTING WITH IRON, ORGANIC COLOR, SILK COTTON, CARRIER BLANKET, TANNIN
EcoPrinting with 'Blankets
Wool - Tribulations of Hand Spinning and Herbal Dyeing: Iron Blanket in a Plant Dye Bundle - A Better Method
Blog DekelDyes
Blankets: A Helpful Tool in Ecoprint - Iritdulman
Best plants for Eco Printing (on fabric and paper) - La creative mama