Dividend investing is a tried-and-true strategy for generating strong, steady returns in economies both good and bad. But as corporate America's slew of dividend cuts and suspensions over the past few years has demonstrated, it's not enough simply to buy a high yield. You also need to make sure those payouts are sustainable.

Let's examine how Quad Graphics (Nasdaq: QUAD) stacks up. In this series, we consider four critical factors investors should examine in every dividend stock. We'll then tie it all together to look at whether Quad Graphics is a dividend dynamo or a disaster in the making.

1. Yield
First and foremost, dividend investors like a large forward yield. But if a yield gets too high, it may reflect investors' doubts about the payout's sustainability. If investors had confidence in the stock, they'd be buying it, driving up the share price and shrinking the yield.

Quad Graphics yields 5.5%, considerably higher than the S&P 500's 2.1%.

2. Payout ratio
The payout ratio might be the most important metric for judging dividend sustainability. It compares the amount of money a company paid out in dividends last year to the earnings it generated. A ratio that's too high -- say, greater than 80% of earnings -- indicates that the company may be stretching to make payouts it can't afford, even when its dividend yield doesn't seem particularly high.

Quad Graphics doesn't have a payout ratio because it didn't generate earnings last year. But a huge chunk of those losses were restructuring charges. The company only paid out 12% of free cash flow.

3. Balance sheet
The best dividend payers have the financial fortitude to fund growth and respond to whatever the economy and competitors throw at them. The interest coverage ratio indicates whether a company is having trouble meeting its interest payments -- any ratio less than 5 times is a warning sign. Meanwhile, the debt-to-equity ratio is a good measure of a company's total debt burden.

Quad Graphics has a debt-to-equity ratio of 119% and an interest coverage rate of 2.6 times.

4. Growth
A large dividend is nice; a large growing dividend is even better. To support a growing dividend, we also want to see earnings growth.

Quad's earnings before taxes (excluding unusual items like those pesky restructurings) are basically flat since 2007. The company began paying its $0.20 quarterly dividend in May 2011.

Apologies for the tangent, but I think I vaguely recall visiting a quad graphics plant for an elementary school field trip many years ago. It was pretty fun. Go Wisconsin!

The Foolish bottom line
So is Quad Graphics a “dividend dynamo?” Perhaps. The company has a high yield and modest free cash flow payout ratio. Dividend investors will want to keep an eye on how the company is able to grow earnings while hopefully reducing its debt burden in the future. If you're looking for great dividend stocks, check out "Secure Your Future With 11 Rock-Solid Dividend Stocks," a special report from the Motley Fool about some serious dividend dynamos. I invite you to grab a free copy to discover everything you need to know about the 11 generous dividend-payers -- simply click here.

Ilan Moscovitz doesn't own shares of any company mentioned. You can follow him on Twitter @TMFDada. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insightsmakes us better investors. The Motley Fool has a disclosure policy.