There are two basic types of paint you find in your home improvement store’s paint department: latex and alkyd. Each has its strengths and its best application suggestions.
Latex (Also Called “Water-Based”) Paints
These offer the easiest application and soap-and-water cleanup, are the fastest drying, and have less odor than solvent paints. Latex performs well on interior walls and ceilings; its quick drying time prevents the kinds of ripples and sags that can occur with slower-drying alkyd finishes. For brick, concrete, and cinder block, only latex should be used.
TIP: Doityourself’s painting consultant Edward Kimble, author of Interior House Painting Blog, adds, “Although it is true that latex paints dry fast and will not sag. they do run. Go back over what you have just painted after about ten minutes and pull the drips out of the painted surface, and also to check a few more times, paying special attention to corners, like on window frames.”
Alkyd (Commonly Called “Oil-Based”) Paints
This type generally cost more than latex. Though interchangeably referred to as "oil-based," they're not the same thing as the traditional oil-based paints they have largely come to replace. Application requires patience - thin coats are generally necessary to avoid problems like sagging and streaking, and the drying time is usually longer than latex.
The upside is a paint job that stands up beautifully to long-term wear and tear. Scrubbing off dirt and scuff marks won't harm the paint. Alkyd paints are the superior choice for painting floors and metal surfaces. Oil-based paint in many ways is easier to work with because it does not dry so rapidly, but cleanup is more difficult. Clean up any splatters or drops from oil base paint immediately with paint thinner, likewise latex paint with water. The fumes from Alkyd paint make it necessary to wear a respirator when using it, although you should always well-ventilate any area when painting.
Tip: Edward advises, “Remember - oil and water don't mix. What's on your walls right now? For best results, apply the same type of paint that's already there. To determine whether existing paint is oil based or latex, put some denatured alcohol on a rag and wipe the surface. If paint comes off onto the rag, it is latex. If not, it is oil or epoxy based.”
Edward Kimble, professional painter and author of Interior House Painting Blog, contributed to this article.