Fiebings oil dyes and spirit dyes are the same thing. The spirit is most likely denatured alcohol or similar. What they call their Pro dyes have more pigment in them I believe. They are getting rid of the oil name. And yes tbere low voc and Tandy eco products are water based. So they can sell them in California. Lol. And I dye the edges with the same dye I dye the belt with.