I usually mix about two Kilos of this mix and place it in a large plastic pickle jar. I place the lid on the jar and then roll it about the studio for a while to mix the ingredients well.
Whenever I need a color under-glaze I use 5 parts of dry mix to one part stain. I add water and mix well and let decant overnight. The next morning I pour off the excess water and the slip is ready to use. I might add a few drops of water as the slip thickens during my painting session.
I cannot remember where I got this recipe. I think it was from one of my Ceramic Monthly editions years ago. The artist who gave the recipe use the dry mix with a liquid mix consisting of 30 Grams of Gum to 128 oz of water to be use in the liquit part of the mix.
Then One would mix 1000 cc of antifreeze (non toxic) with 1000 cc of water and to this one would add 500cc ot the gum mix.
I tried this but found the smell during firing to be too strong even with my ventilation.