Green, Greener, Greenest

Today's investigation concerns dye concentration. When working with something like watercolor or ink, it's pretty obvious that diluting with water will make a color paler. I thought dye was different. You put four things in a dyebath: fabric, dye, various helper chemicals, and water. I thought the depth of shade was all about how many grams of dye vs. how many grams of fabric. How long the fabric swirled in the dye bath mattered, but the amount of water didn't, beyond having enough to let the fabric move freely.

But that's all for regular dye baths, and this is low-immersion dye bath. And it would appear that the dye-to-water ratio matters. A lot.

Here's the test.I put identical amounts of green dye (1 part Fire Red, 8 parts Lemon Yellow, 6 parts Cerulean, using my weighted proportions.) into each cup, and added 10, 20, 40, 80, 160, and 240 ml of water to each cup. Each cup got a 5"x5" square of fabric. After 20 minutes I added a teaspoon of soda ash solution to each cup. Then they sat for 2 hours.


The results are clear. More water, lighter shade.


Here are the fabrics all rinsed out.


The next question was how much the amount of fabric matters. I made two concentrations of the same brown dye, one four times as strong as the other. I put a 5"x5" and a 10"x10" square in each concentration. The four cups have the same amount of liquid.




(Sorry the order isn't logical; big squares are on the outside.)

Before the fabric is rinsed out, the impact of dye concentration is exaggerated.

Here they are after washing out excess dye. Just like with the green test, dye concentration matters the most, but the amount of fabric matters too. The small squares show the impact of dye concentration more clearly. The big squares are pale and paler, so the difference is less obvious.

The two darker squares on the right both had the same dye concentration and the same total amount of dye, but the larger square had 4 times as much fabric, so it's paler. The difference is less dramatic than between the two small squares, but it matters.

The darker large square and the paler small square had the same proportion of dye to fabric in identical amounts water. The one in the higher-concentration dye-bath is darker.

This tan is 5 parts Fire Red, 3 parts Lemon Yellow, and 2 parts Cerulean Blue. It's pleasing to make a real neutral. On my screen, this looks a little pinkish, but in life is just a little too green. Next time I'll up the Fire Red just a bit.