Masonry Walls and Ceilings. Interior masonry walls and ceilings above grade may, in general, be painted in much the same manner as plaster surfaces. Here again, it is necessary to allow adequate time for the masonry to dry before applying paint and, in addition, attention should be given to the preparation of the surface. When decorating a wall containing Portland cement (concrete, for example), it is essential to take precautions against the attack of alkali. For this purpose, alkali-resistant primers such as rubber-base paints may be used when oil paints are to follow.
Inside the house is where acrylic shines. It dries faster than other types, and it keeps its color better, without yellowing. One disadvantage: It costs more.
A good interior paint job is often 50% preparation and 50% painting. Do not rush in preparing the surfaces in your eagerness to get at the brush or roller. If you do not prepare the surfaces properly, you'll be back with the paint brush or roller in a few months.
OK, let's get started. Step one...supplies. You need a flat brush, a fan, a small detail brush and a couple of Filberts. A filbert is a rounded edge brush that lets you maneuver the paint easily without going outside the edges. Ultimately buy brushes that you like though, and make them work. Fans allow you to blend, for example. I use fans a lot and it's how I graduate color throughout my images. Everything I paint is by hand....no airbrushing or assistants. I want it to be an expression of me and nobody else. You also need an oil painting medium to mix with the oil paint to make it more fluid, and to speed or slow the drying process. Whichever you prefer. Go to the art store and don't be afraid to ask for help....they'll love helping you! A medium is merely an additive liquid which increases gloss, makes it flow easily, preserves the finish over time, keeps it from yellowing. I personally love Galkyd and Galkyd Lite. If that isn't available, buy a medium that looks like liquid amber and is kind of thick. Don't buy watery looking mediums....too hard to work with.
THE BRUSHWORK. Depending on the art movement and personal peculiarities of the artist, the brushwork can range from delicate and almost invisible to rough and plastic.
Paint Selection. Most paints are purchased ready-mixed but, in their selection, consideration should be given to the fact that surfaces vary in their adaptability to paint and atmospheric or other conditions having an adverse effect on paint performance. In addition to the normal weathering action of sun and rain, outside house paints are sometimes exposed to other attacking elements, such as corrosive fumes from factories or excessive amounts of wind-driven dust.
A large whitewash brush is best for applying the wash. One should not attempt to brush out the coating, as in applying oil paint, but simply spread the whitewash on as evenly and quickly as possible.