What is wrong with acrylic?
Now that paint manufacturers talk of acrylic paints as if they were the saviours of the environment, my dislike of them has become a burning hatred. They are fairly safe to use it is true. But acrylic is plastic. It is a petrochemical product. The paint may have few (if any in some specialist concoctions) volatile organic compounds, but the ingredients themselves contribute to global warming. So, I dislike acrylic paints because they lie about being green.
As a former archaeologist (of twenty years), I also dislike acrylic simply for not being traditional. "Dead Salmon" is a Farrow and Ball name for a dark pinkish biege. It "comes from a painting bill for the library at Kedleston of 1805". This should be music to my ears. But to apply it as an acrylic eggshell, is to use paint from the very end of the twentieth century. Farrow and Ball do not mention the "a" word in their colour chart. The plastic paint is 200 years from that painting bill.
I used to dislike acrylic paint because it wasn't very good. But that's going back twenty years. It is now quite tough and in tests it seems to outlast oil-based gloss paints even used outdoors. It does have advantages and disadvantages when compared to gloss (alkyd resin paints). It is easier to clean up (water). It doesn't smell. It dries quickly. These are huge advantages. Gloss tends to run and dribble. This does seem to give another advantage to acrylic, but hold on. This tendency of slow drying paint to slump actually ensures a smoother finish. The drawback of the quick drying, thicker acrylic is that it stays where it is and tends to maintain brush strokes. There is also the tendency for overlap and build up, often on corners.
Acrylic cannot be reversed
This is a disaster for people with a passionate love of old properties. Acrylic paint and varnish cannot be removed with conventional paint stripper. Architectural salvage yards won't touch a door that has had an acrylic varnish applied directly to the timber. Ok, if you are painting your skirting boards you probably aren't worried about taking the paint off. But suppose you use an acrylic varnish on your beautifully stripped doors. And suppose you decide to use a coloured acrylic varnish because you want the yellow pine to be a deep mahogany color. Oops! That's when you discover that acrylic varnish sits on the wood surface and doesn't penetrate like oil or old polyurethene varnish. The colour sits on the surface and obscures the grain. Double oops! The acrylic varnish dries superfast and brushstrokes are clearly visible. Triple oops! Because it is so fast drying, overlapping brushstrokes double the amount of varnish on the timber and intensify the colour, leaving dark patches all over. Quadruple oops! Because it is water based, the water has been soaked up by the timber's fibres and they have become swollen. The whole surface is as rough as a badger's, well, rough bit. Now you have to sand the surface more than just lightly (denib is the trade jargon). Oops for the fifth time! (although by now it is swearing and blinding, not a genteel "oops") even a light sand takes plenty more off any high points (mouldings and corners for instance) and the colour of the varnish has gone, leaving light-coloured patches and lines all over the door as well as the dark patches where the brushstrokes overlapped. The job is done, it cannot be undone, and it looks like hell. Only thing to do now is paint it!
What do you use on walls?
We don't supply anything and have no advice other than use emulsion. Don't use emulsion with added acrylic. The manufacturers sell the idea on the grounds that it is hard wearing and wipeable. It is. But the added acrylic is plastic. Don't smother your traditional plaster with plastic. It won't be able to breathe and, sure as fate, there will be trouble in the future. If you have plasterboard walls, you can go ahead for all I care, I don't think of plasterboard as real architecture.