I had a few white T-shirt I found the day before (and one from salvation army) those can't be printed using the discharge paste cause there's no dye to discharge of. So moving to plan B - printing the first layer of the stencil using paint instead of discharge paste.
First of all, you need to mix the paint.
The instruction on the bottle of the fabric medium say to mix the medium and the paint in a 1:1 ratio. I found out that this lead to the paint being too watery and then I don't get lines as crisp as I want them to be, so I 1:2 ration of medium and paint.
Pour them onto the plate and mix together with a stick or the other side of a brush to even consistency - should be the same thickness as honey or cream cheese.
If oyu don't have the exact color you want, you can also mix different colors together with the medium.
Just notice that all the different colors mixed and that there aren't any lumps that would stain your print.