Thinning and Misting every coat

[Taffypainter]

An old decorating lecturer from college said it wasn't just emulsions indoors or masonry paints he thinned

He would always ease up even finishing coats very slightly for better coverage

What he did feel was that the advice for mist coating was however far too liberal and he would put about a pint , maximum , in 5 litres of matt emulsion to prime plaster

I stick with that , I have seen decorators make a right old mess of misting

[dewaltdisney]

The results will depend on how much suck there is in the new plaster. If the water is sucked out of the first coat too quickly it will leave the body of the paint not absorbed and not binding properly in part of the areas covered. Future full-strength coats may pull the first coat off. The mist coat is a variable guess and that is why you will see different ratios quoted by different people. Quite frankly anything between 50% and 75% should be safe for most new surfaces as the dilute mix gets pulled into the surface and seals it giving a perfect substrate for the finishing coats. it does not matter that the opacity is not great it is the absorption that is important. Your tutors ratio is around 80% rough maths.

DWD

[Taffypainter]

He's got it just about spot on I think

Summer time can use a bit more thinning in my experience

I have never gone anywhere near 60 percent never mind 50 50