Hi VivK... The first thing to learn...there is NO such thing as a tried and true recipe.  next thing to learn is to  google "aubergine gloss glaze"   From clayart site....   Eggplant Purple -- cone 6 oxidation Kona F-4 feldspar 45.7 Flint 15.2 Talc 12.7 Gerstley Borate 12.9 Dolomite 9.0 EPK 4.5 add: Bentonite 1.0 Cobalt Carb. 2.0 Manganese Carb. 5.0 You MUST Test it first... your results may and probably will vary. glaze components are different from place to place and even from year to