I usually prefer to paint over a black base coat. It helps with shading, if you miss a bit its more forgiving and, of course, Skull White spray is crap. It has never worked, twelve years in this hobby and it has never worked: it bobbled horrendously and even if it didn't it never covered consistently. The Ceramite White base paint was somehow worse. I've tried to game the system by going up to white through grey and through blue but it takes so many layers that I lose the detail of the model.
And now I'm painting Lizardmen, whose bright blue skin tones are so arduous if you start from black. Having painted a dozen Skinks like I finally broke and decided to try the new Corax White spray.
And it works! Miracle is miracles it bloody works: it covered flat and consistent. I did a test Saurus and then a few other things that had sanded bases to make sure the thing actually worked and I hadn't just got lucky. Yet four more Saurus, two Salamanders and a Skink Priest not one came out of the experience badly. I even tempted fate to make sure! The Skink Priest in question is the one with the cloak of feathers, which is my favourite of all Lizardmen minis so if it was going to fuck up it would fuck up good and hard on that one.
Just about the only flaw in it is guessing whether you've covered the whole of a Finecast model since the spray is inconveniently resin-coloured. Still, Finecast is not long for this world so that won't be a problem for long.
So, yes, finally I can paint from white which opens out the options rather. I imagine this'll be especially useful once I start painting Bretonnian Knights.