Name: Jasmyn

Country or region: California, USA

Message: Hello, my name is Jasmyn. I am in 8th grade.  I am working on a science project about dyeing fabrics with natural dyes.  The information I got from your website has been very helpful.  I tried a few recipes and had good luck.  The samples will make a good presentation for my project.

I would appreciate it if you would please answer a couple questions that I can include in my project:

1.   Do you think natural dyes are better than synthetic?

No, by most criteria, most natural dyes are inferior to the best synthetic dyes, because they are harder to apply and more expensive, and natural dyes usually require toxic mordants, and tend to fade more quickly when washed. Any color that can be obtained from natural dyes can also be obtained with the correct mixture of synthetic dyes, but the opposite is not always correct; some hues are very difficult to obtain with natural dyes. (Some natural dye enthusiasts claim that natural dyes make more beautiful colors than can be obtained with synthetic dyes, but this is incorrect, the result of a lack of knowledge of color mixing.)

About mordants: Most natural dyes will not stick to fabric unless the fabric has been treated by boiling it with a mordant such as alum (potassium aluminum sulfate), chrome (potassium dichromate), copper, or tin, but mordants can be dangerous: each of these mordants has caused human deaths due to swallowing them. Alum is the safest of the metal salt mordants, because it takes one ounce to kill an adult who swallows it, instead of just a few grams. Unlike natural dyes, most synthetic dyes can be used without mordants, instead requiring safer chemicals such as sodium carbonate (soda ash) or dilute acetic acid (vinegar).

2.   Are there advantages to using natural dyes?

A key advantage is being able to grow your own dye, though it can require a surprisingly large amount of a dyestuff to produce enough dye to use.

Another is that some natural dyes are safe to eat (although some other natural dyes are poisonous, and mordants are poisonous); for example, cochineal is commonly found, named "carmine", as a coloring in pink-colored yogurts or in lipstick.

The biggest advantage of natural dyes is simply aesthetic; the idea of using natural dyes is very pleasing.

3.   What are the disadvantages of using natural dyes?

Unfortunately, the disadvantages of natural dyes are many.

A much greater quantity of a natural dyestuff is needed to dye a given amount of fiber than for a synthetic dye. For example, one pound of cotton can be dyed with 5 grams of Procion MX synthetic dye, or with half a pound (230 grams) of goldenrod flowers. 

As a result, one of the most important disadvantages is that natural dyes cost many times more than synthetic dyes. In many cases, if you buy natural dyes, it will cost you $5 or $10 or even more to dye the same amount of fabric that would cost only about 50¢ to dye with a synthetic fiber reactive dye.

Natural dyes fade much more quickly than synthetic fiber reactive dyes, so clothing is discarded sooner, resulting in a greater cost for each year of wear, as well as the cost to the environment associated with the production of fiber for new clothing. Surprisingly, this means that synthetic dyes are not necessarily less eco-friendly than natural dyes.

4.   What natural sources are more successful and give vibrant color?

Indigo is a dye that is usually now derived from synthetic sources, but it can be extracted from several different species of plants, and produces a beautiful bright blue. The synthetic indigo used to dye blue jeans is chemically identical to natural indigo. Cochineal is a wonderful red dye, derived from the dried bodies of an insect that infests prickly pear cactuses. The spice turmeric is easy to use, because it does not require a mordant, and it is very concentrated, so you can easily produce a beautiful bright yellow by boiling your fabric with it; unfortunately, it fades rather quickly upon exposure to light. Quercitron, a natural dye made from the inner bark of black oak trees, makes a better, longer-lasting yellow dye, but it is difficult to buy. Logwood produces purple or black depending on what mordant you use it with. 

Thank you very much for your input to my Science Fair Project.

Good luck with your project. I'm glad you've found my site to be helpful.

(Please help support this web site. Thank you.)