Quote Originally Posted by mabman View Post
Is it really that popular?
My assumption: it might become very popular if it were an improved, reliable, off-the-shelf product.

Simply because it is staining, but not toxic, and the results I have seen so far from Nescafé-and-Folgers homebrew stuff are quite impressive for such a simple recipe. With some experimenting and good scientific knowledge of photo chemicals it might become an excellent developer.