Each dye in this kit is a 3 oz jar of Procion MX fiber reactive dye powder, pre-mixed with a fixative. To use, add a small dash of moisture — a light spritz or a damp surface — and the dye activates and bonds permanently to natural fibers including cotton, rayon, linen, and silk. The six shades in this kit are curated to work together, gradating from light to dark (or warm to cool) so they can be applied side by side or layered without clashing. Sourced from Dharma Trading Company. Storage: keep lids sealed, store in a cool dry place away from direct sunlight. Shelf life is 1–2 years when stored properly.