Tint will not lift tint. I keep reading this BUT where I work they often use say a 6 or a 7 shade (20 vol) with either a 9 or a 10 (30 vol) for 2 tone foils. I have seen this done lots of times on hair treated exactly the same way a couple of months previously. Now then if tint will not lift tint how come the lighter shade covers any hair previously coloured by the 6 or 7? In other words it looks great!