I am a cynic by nature, but the quarterly results that PPG Industries (NYSE: PPG) just reported have made me a believer. Sales increased 15% year over year. Adjusted earnings per share from continuing operations were up 28%. The volume of product sold increased by just under 5% relative to the year-ago quarter.

While the headline numbers are nice, the segment operating results are even better. Each one of PPG's operating segments reported sales increases of 10% or more. PPG's results seem even more impressive in light of the slowing U.S. economy. Judging from today's 4%-plus gain in PPG's stock price, investors apparently expected weaker results. While a large portion of its products are used in the manufacture of new items -- whether for industrial users or consumers -- PPG's diversification should keep it fairly safe from a slowing economy.

The U.S. economy will matter less to PPG in the future than it has in the past. PPG's recently closed acquisition of Netherlands-based SigmaKalon will push PPG's U.S.-based revenues down substantially going forward, to around 50%.

While things are going well for PPG, its good fortunes have not been shared equally throughout the paint and coatings industry. Peer Sherwin-Williams' (NYSE: SHW) shares, for example, are off around 10% over the past week. Investors interested in PPG should keep an eye on Sherwin-Williams' results in two weeks, as they'll give a better read on how badly the economy is hurting the industry and just how well PPG is navigating the muddle.

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Fool contributor Michael Goode is an investor who lives in St. Louis. Going by the handle EverydayInvestor, he is currently ranked 32 out of more than 81,000 players on Motley Fool CAPS. He has no position in any company mentioned, although his house is painted with PPG's Porter brand paint. The Motley Fool has a disclosure policy.