Thanks for all the hard work you put in.
Did you use a tool, generator with parameters, make them by hand, or run a regular icon pack through a filter (In theory some people can take existing icon files and run them through a filter program, Like Pixelme, and modify them to suit your own project)?
I appreciate making core files free and the whole collection a payed item. That a unique way to market without making 2 seperate projects and a clever way to do it!