Industry that peddles gilt-edged sentiments turns gilt-edge profits, too

Business and sentiment might seem like unlikely partners, but their marriage has spawned the lucrative American greeting card industry. From the lace-and-satin valentines of the 19th century to the computer-generated musical cards of the 1980s, sales have risen steadily to $7 billion a year. Neither inflation nor recession has hampered growth.

Marianne McDermott, executive director of the Washington-based Greeting Card Association, calls the industry recession proof: ''Even when things are bad, people need to express sentiment. Greeting cards, after all, are one of the only items purchased solely to give to someone else. When the economy plunges, many retailers find customers opting for cards instead of gifts.''

But the biggest boost to the industry comes from changes in American society. More women work, but women continue to buy close to 90 percent of all greeting cards. The new mobility, diversity, and self-consciousness of American life have propelled sales of friendship, blank, and other ''everyday cards'' to new heights, as marketing director Steve Crews of Hallmark Cards Inc., of Kansas City, Mo., well knows. Hallmark sells about 40 percent of all American greeting cards.

''With people moving farther away, there's a greater need than ever to keep in touch,'' Mr. Crews says. ''Yet people are busy. The greeting card offers an opportunity to keep in touch without investing a lot of time.''

Messages have become more specialized, reflecting the diversity of the American public. Cards abound for minorities and those involved in alternative life styles, as do those for working women to send friends and colleagues, parents to send child-care workers, and children to send stepparents.

The iambic pentameter of yesteryear has given way to bolder, more direct messages. Fathers have become nurturers as well as breadwinners. Christmas - the biggest seller of cards, although its lead has been slipping - continues to reflect the temper of the times. Religious themes have become increasingly popular. So, too, have Easter cards (eclipsing Mother's Day), Halloween cards, chocolate cards sealed with flavored glue, pop-up cards propelled by rubber bands, and high-tech cards with lasers and computer chips. Hallmark is at work on a $20 million center to further such high-tech expressions.

But Hallmark is one of the elite few. The circle of prosperous greeting card manufacturers has narrowed considerably. According to a 1983 study by Business Trend Analysts of Commack, N.Y., the top four companies (out of roughly 150) accounted for 80 percent of the industry's sales in 1981, compared with 37 percent in 1954.

Competition between the top two - Hallmark and American Greetings Corporation of Cleveland - has intensified. Hallmark has expanded into lower-priced stores, American Greetings into upscale ones. The competition extends to the licensing of greeting card characters as well. American Greetings is No. 1,thanks to the success of Strawberry Shortcake, Ziggy, and Holly Hobbie characters. Hallmark's Shirt Tales, however, totaled $100 million in retail sales (e.g., stuffed animals, toys) in 1981. The licenser draws 6 to 10 percent of total sales, according to Business Trend Analysts, which predicts a bright future for the practice.

Card giants have also stepped up their moonlighting in the gift-wrap, stationery, and party-goods businesses. But many of their smaller colleagues find it difficult to stay in business, never mind diversify. Says the Greeting Card Association's Ms. McDermott: ''There are more greeting card companies now than ever before, but if they don't get up to a certain volume they just don't last.''

Maine Line Company of Rockland, Maine, is one of the survivors. The company, founded in 1979 by two former film company readers and researchers, Perri Ardman and Joyce Boaz, grosses $1 million a year with messages for and about women. The sentiments are decidedly unsentimental. One card depicts a world without men as ''no crime and lots of happy, fat women.''

''We're providing something women want and need, but competing for space in stores with the giants is hard work,'' says Ms. Ardman.