Goldwell System Thickener Thickening Fluid 3.4 oz. A concentrated Thickening Fluid that empowers you to control and customize the consistency of your color and lightener products.- Works with Topchic, Nectaya, Colorance, SilkLift, SilkLift Control, Oxycur and New Blonde.- Whatever consistency you choose, all colors stay true to tone while the processing time remains the same.