Tie-Dyeing with Tannins and Iron

Contributors

Assistant Professor | Fashion Institute of Technology

Top image: orange fabric mordanted with iron, bottom image: an orange and blue striped cotton handkerchief

Summary

This laboratory experiment uses tannins from acorns and iron from rusted metal to color cotton fabrics. It explores renewable dyes, oxidation and reduction reactions, and the creation of organometallic coordination polymers from waste resources. It's suited for introductory and non-major students but can be extended into upper-level undergraduate courses as well.

It's well suited for the fall where students can collect plant matter to dye with, and generates oranges, reds, blues, and blacks perfect for the Halloween and autumn seasons.

By using renewable and waste feedstocks, you can address green principles while having some fun tie-dyeing in the lab.

Keywords

Submitted by

Julian Silverman

Safety Precautions, Hazards, and Risk Assessment

Rusted iron metal should be handled with gloves before adding to the vinegar solution. Oak leaves and acorns should be dried before use and extraneous debris removed before processing. Tannic acid and iron acetate solutions are safe to handle with gloves, goggles, and a lab coat. When heating liquids care should be taken because the solution can stain fabrics. Wash fabrics with soap and dry before use. A test strip of dyed and mordanted fabrics should be worn as a bracelet for one week to check for any adverse reaction of the skin before fabrics are worn.

Teacher Recommendations or Piloting Data (if available)

Test this out beforehand, the colors will vary based on the leaves and the iron. It takes about two weeks to generate a strong iron mordant. You can use old cotton T-shirts (they don't need to be white) to dye. It also works well with other natural fibers such as wool and silk. A variety of different natural plants work with the iron mordant, including marigolds, onion skins, and avocado pits. Use what you have!

You can have the students collect the leaves, or instead use tannic acid powder and create a brown solution instead. Similarly, a mixture of iron acetate or iron sulfate can be used as the mordant without waiting two weeks.

Digital Object Identifier (DOI)

https://doi.org/10.59877/SQGM1012

Related Learning Objects

Make Sustainable Fabrics from Seaweed

Other notes/information

Material in the PDF:

Laboratory Manual
Extra Credit Assignment (Foraging for Acorns and Oak Leaves)
Pre/Post Lab Assessment
Suggested Reading for Natural Dyes and Fabrics