Testing out my options for fabric print-dying. I mixed the chemical water using directions from Dharma Trading Company: a quart of warmish water, 3/4 cups of urea, and 2 teaspoons of sodium alginate. I left the water for 2 hours at room temperature and then mixed up my colors. For the test colors I used 1/4 cup of chemical water per color. To each color I added a 1/4 teaspoon of soda ash and 1/4 teaspoon of procion dye.
First finding: 2 teaspoons is not nearly enough sodium alginate. The paint did not have enough body to cling to the stamps and was difficult to apply using a paint brush. I added 2 more teaspoons to the remaining 3 cups of chemical water. This is a little too thick and I had to thin it with water so it wouldn't gloop. Conclusion: 4 teaspoons of sodium alginate will probably be perfect in a quart of water.
These are the test strips that were washed after 6 hours of setting. They turned out great and I don't think I need to wait any longer. I will use longer setting times for convenience if necessary. The red colors (jungle red and amethyst) show more bleeding than the blue based shades so I'll have to be careful there. It's pretty clear that the whole 1/4 teaspoon of dye is not necessary for a 1/4 cup of chemical water so I'll reduce that especially with the reds.
And for the grand finale here is some finished yardage that I stamped using a homemade stamp inspired by these. The experiment has been a success.