Juanma
Mac-Valve Maestro!
Many thanks Ian I'll have a look at it because so far it's only given me problems.Juan, Blue shift can be a problem, it can also be a bonus for some paintings if you need a blue or cold colour
You can negate the problem somewhat by adding a few drops orange or light brown to the white to tint it ever so slightly, there are numerous videos on how to get around blue shift.