Painting walls and ceilings and painting home exteriors are some of the most popular DIY fix-ups by homeowners. Although almost everyone paints from time to time, how many of us really know what we're buying and applying? Just what is this stuff, and what do we need to know when we buy it. Is the $7-per-gallon paint as good as the $35-per-gallon paint? And what about latex paint and oil-based paint?
It can all be pretty confusing and, as a result, many people simply base their decision on price and get the cheapest paint they can buy only to find out that they need to paint and re-coat and re-coat and re-coat again, just to get the cheap paint to cover.
In this article, we'll talk about the basics of paint: what it is, what types there are, which type to use where and how to choose the right sheen.
What Is Paint?
Paint is a mixture of four basic ingredients: pigments, resins, solvents, and additives. Pigment is the color, and resin is the binder, or glue. Solvent is the carrier that makes it all liquid and evaporates as the paint dries. Additives provide specific performance characteristics, such as stain-blocking or mold-killing properties.
Cheap paints have a higher percentage of solvents per volume than better pains. As a result, there can be up to 50% less pigment and resin in a gallon of cheap paint.
This means that most of what you are applying with cheap paint is solvent (water or mineral spirits), which just evaporates, leaving little pigment behind. This is why you have to re-coat and re-coat up to four times with low-quality paint before enough pigment is left behind to cover the color underneath.
So learn from the pros, who value their time: buy the best paint you can afford and avoid having to paint more than twice. Look for manufacturers with a good reputation, and check the label looking for products containing about 45% pigment and resins per volume.
Water-Based vs. Oil-Based Types of Paint
All paints basically fall into two solvent categories that define their type: water-based or oil-based. Water-based paint actually has water as a solvent, but just to confuse everyone this paint is most commonly called "latex" even though it does not contain latex. Many water-based paints are made with acrylic and may be called "acrylic latex." The label "oil-based paint" is equally confusing, because it isn't actually made with oil; it has a solvent of mineral spirits (also known as paint thinner) or alkyd resin. Alkyd can be thinned with mineral spirits, and latex paint is thinned with water. At the paint store, you'll be understood if you use the terms latex paint or alkyd or oil-based paint.
Water-Based (Latex) Paint
Latex paint is the most common type of paint for home use for several reasons:
- Cleans up with soap and water.
- Environmentally friendly; typically contains fewer VOCs (volatile organic compounds).
- Excellent performance.
- Remains flexible, withstands movement.
- Can prevent mildew and moisture.
- Available in many colors and sheens.
You can use water-based paint in almost any application in the home, from exteriors and trim to interior walls and woodwork.
Alkyd paint is not commonly used in home painting applications. At one time, these paints were the standard for bathrooms and other "wet" areas, since they were easy to scrub, had a higher sheen and were more durable than the early latex paints. That is no longer true, however, as many latex paints now equal and sometimes outperform alkyd paints.
When used in the home, alkyd paints are most commonly reserved for areas subject to heavy wear or prone to impact. These include trim, floors and sometimes cabinets. Another benefit to alkyd is it has a longer drying time than latex paint, so it does not show brush strokes as much, an advantage when painting trim, woodwork, and cabinetry.
Some disadvantages of alkyd paint include:
- Typically more expensive than latex paint.
- Odor-intensive when drying and typically contains more VOCs (volatile organic compounds).
- Requires cleanup with chemical solvent (mineral spirits, or paint thinner).
- Some local municipalities restrict the use of this paint because of the hazardous materials it creates in the waste stream.
Another consideration in selecting the proper paint is a factor called paint sheen. Paint sheen refers to how shiny the dried paint surface becomes when dry. There are four basic sheens:
- Eggshell or Satin
Flat paints have the least amount of sheen. The advantages of this are that the paint hides imperfections well and the painted surface creates very little glare. The disadvantage is that is not very washable. If you rub the surface with a damp sponge, the paint may come off on the sponge. For all of these reasons, flat paint typically is used only on the ceilings in homes.
Eggshell paint has a moderate amount of sheen so it hides imperfections somewhat and produces relatively little glare. It's also fairly washable. These characteristics make it the standard choice for all walls in living areas--that is, everywhere except kitchens and bathrooms.
Satin is similar to eggshell and is sometimes a half-step up in glossiness. Some manufacturers offer satin in place of eggshell; others offer both.
Semi-gloss is used in kitchens, bathrooms, laundry rooms and similar areas that need the high washability and moisture-resistance of a glossier paint. It's okay to use eggshell or satin in these areas, too, provided the surfaces stay dry, but semi-gloss is a better all-around option.
Gloss paint is used on trim, doors and cabinets because it's tough and highly washable. It also reflects a lot of light, which makes these small but detailed elements pop with color.