Ferrous lactate is a new type of ferrous mordant, offering dyers an alternative to traditional ferrous sulfate. It can be used both as a mordant and a post-mordant to alter or deepen shades. Like ferrous sulfate, it reacts strongly with tannins, shifting them to grey or black, but it produces distinct and sometimes subtler tones compared to regular iron mordants.

This mordant is derived from lactic acid produced from fermented, renewable food sources, making it a more sustainable option.

Applications in Dyeing

• Use as a mordant or post-mordant.
• Especially effective for shading botanical prints and tannin-rich dyes.
• Enhances depth, contrast, and durability of colours.

Notes

• Easily soluble in water.
• Produces different shades than traditional ferrous sulfate.
• Suitable for both dyeing and eco-printing.

Tech Specs

• Appearance: greenish-white crystals or light green powder
• Odour: slight, characteristic
• Taste: mild, sweet, ferruginous (not for food use here)
• Stability: darkens on exposure to air, becomes incompletely soluble
• Storage: keep dry and dark in a clearly marked container
• Safety: wear a mask when handling dry powder

CAS No. 5905-52-2
HS Code 29181100

Note on Other Uses
While ferrous lactate is also used in the food industry as an acidity regulator, iron supplement, and colour-retention agent (e.g. in olives), the Natural Dye Store offers this material exclusively as a mordant and does not recommend it for any other purpose.