DEAR MIKE: I planned to paint several bedrooms in my house and when I went to buy the paint, I noticed a dramatic difference in price. The expensive paint was easily double the cost of the cheap paint. What is the difference between the two, and do you recommend paying the extra money for the expensive paint? -- Tracy C.
DEAR TRACY: I have learned my lesson. When I was young (and dumb), I bid a paint job at a customer's house. I figured out the cost of materials and estimated the time to complete the job and gave the customer the price. She agreed.
I bought cheap paint and it took twice as long to complete the job. The cheap paint took two coats and I took a shellacking. I don't buy the cheap stuff anymore.
There are several factors that go into a paint can and this is one of those cases where you get what you pay for. There is a definite quality difference between cheap paint and expensive paint. Cheap paint is usually under $10 per gallon whereas the expensive stuff is $20-$25 per gallon if you buy it by the single-gallon containers. The price gap closes as you buy paint in five-gallon containers.
Don't be fooled by the manufacturer's names either. Virtually all manufacturers make cheap paint and expensive paint so don't think you're getting a great deal just because an $8 gallon of paint has a recognized brand name on it.
All paint has pigments, resins and solvents in it. With expensive paint, the pigments are smaller and more pure. This gives the paint one of its main attributes: the ability to hide the surface on which it is applied. With cheap paint, the pigments are of lower quality and are larger (this means you get to give the wall two coats of paint instead of just one).
Resins hold the pigments together and create a "film" of paint. High-quality paints use high-quality resins for a more durable finish that lasts longer. You guessed it, high-quality resins are found in more expensive paint.
The solvent used in paint (water for latex paint) is just the carrier for the resins and pigments. Cheap paint has more solvents per gallon than does the more expensive paint. As the solvent evaporates, you are left with the resin and pigment that stays on the wall. So not only does cheap paint have poorer quality resins and pigments, per gallon it also has fewer of them.
If you had a device that could measure the thickness of a coat of paint, you would find something very interesting. Both cheap and expensive paint will go on wet at the same thickness. However, since cheap paint has more solvent per gallon than expensive paint, if you were to measure the thickness of each paint when dry, you would find that the expensive paint leaves a thicker coat.
When you use an airless sprayer you must thin (add water for latex paint) the paint so that it flows easily through the sprayer. You definitely have to thin the expensive paint, but the cheap stuff is usually so thin (I didn't want to say runny) you can spray it right out of the can.
Expensive paint also has additives that minimize mildew and help the paint to adhere to the surface better.
When you buy paint, buy the expensive stuff that is 100 percent acrylic. This may be the case where a $25 gallon of paint is cheaper than a $10 gallon of paint.