Watched a client's gray coverage change over 4 months after I switched her to a lower volume developer
Her roots used to show through at week 3 like clockwork, but after I dropped from 30 vol to 20 vol with a 10 minute longer process time back in March, she came in at week 6 with maybe a quarter inch of soft grow out, so has anyone else seen developer volume matter more than the brand of color for gray blending?