Dynamic's 4 Bottle Greywash set is split across 4 different shades. The specific formulas come from countless tests and years of polling black and grey specific artists to gather a commonality in ratios for the perfect 4 bottle set.
#20- A thin wash and lightest of the set.
#40- A smooth light-mid tone wash.
#60- A deep and silky true medium toned wash.
#80- The darkest of the set, a deep and full-bodied wash.