VIVA DECOR-Ferro Metal Effect Color. Ferro is a totally unique special effect color that delivers a real metallic finish. Use it to decorate and enhance any project both indoors and out. It is a permanent water-based acrylic and can be used on paper, cardboard, ceramic, wood, stone, terracotta, and plastic. It is suitable for use on walls and can also be used by artists as a sub-surface. Each package contains one 90mL bottle of Ferro. Available in a variety of colors (each sold separately). Conforms to ASTM D-4236. Imported.