Paper costs are rising mail rate hikes are looming and competition from new media continues to grow. Yet marketers’ use of direct mail and other printed materials is stronger than it’s been in years. Thanks to variable-data printing companies can now tap purchase-history databases to design create and print entirely personalized catalogs that cross-sell products and services to individual consumers. They can also combine print with other media in the evolving discipline known as cross-channel marketing. But whatever strategy a company adopts experts note the challenge is the same: Finding the right way to communicate with customers.