Pro dyes pigment is oil based. Hence why originally they were called “Oil Dye”. The carrier is still alcohol. They changed the name because it caused confusion. That’s why they changed to “Pro Dye”. 90% of the time I use an airbrush to dye. I only use Pro Dye as it works best for me. Dyeing is an art more than a science. Different hides or even different parts of a single hide will dye differently. That’s why I prefer the airbrush. I can layer on dye till I get the color I want.