Ferrous sulfate heptahydrate is the iron salt most commonly used as a textile mordant. Historically known as copperas, it produces darker and moodier hues than aluminum. Yellow dyes turn green, red dyes turn purple, and logwood dyes turn black when they are “saddened” with iron. Ferrous sulfate can be applied with good results to all textile fibers, but care must be taken to apply it correctly or it can damage the fibers. When wool is mordanted with ferrous sulfate, a large amount of cream of tartar should be added to the mordant bath (approximately 2.5x the amount of ferrous sulfate). Cotton and linen should be treated with a tannin first, and then allowed to soak in the iron mordant bath at room temperature. Check out our guide to Mordanting with Ferrous Sulfate for more details. Sold in jars containing 100 grams.
WARNING: This product contains iron. Accidental consumption of iron-containing products is a leading cause of fatal poisoning in children under the age of 6. Store this product and all mordant baths made with it out of reach of children. In case of accidental ingestion, seek medical assistance. May cause skin or eye irritation. Wear gloves and a mask while handling. SDS available on request.
Ferrous sulfate heptahydrate is the iron salt most commonly used as a textile mordant. Historically known as copperas, it produces darker and moodier hues than aluminum. Yellow dyes turn green, red dyes turn purple, and logwood dyes turn black when they are “saddened” with iron. Ferrous sulfate can be applied with good results to all textile fibers, but care must be taken to apply it correctly or it can damage the fibers. When wool is mordanted with ferrous sulfate, a large amount of cream of tartar should be added to the mordant bath (approximately 2.5x the amount of ferrous sulfate). Cotton and linen should be treated with a tannin first, and then allowed to soak in the iron mordant bath at room temperature. Check out our guide to Mordanting with Ferrous Sulfate for more details. Sold in jars containing 100 grams.
WARNING: This product contains iron. Accidental consumption of iron-containing products is a leading cause of fatal poisoning in children under the age of 6. Store this product and all mordant baths made with it out of reach of children. In case of accidental ingestion, seek medical assistance. May cause skin or eye irritation. Wear gloves and a mask while handling. SDS available on request.
