Kansas City, Mo ? Hallmark Cards Inc. twice experimented with selling Veterans Day cards and twice decided the market wasn’t there. But that was before Sept. 11, and before Keri Olson made them a personal crusade.

Last Veterans Day, Olson wanted to get a card for her father, who fought in the Vietnam War.

“I think with the events of Sept. 11, I began to understand all that he had sacrificed. I really wanted to tell him,” she said.

Employed by Hallmark at its Kansas City, Mo., headquarters the past two years, she knew the company did not make a specific card for that day. So she chose one that simply expressed appreciation and on Nov. 11 gave it to her father, who was in the Army and had received a Purple Heart.

“When he got this card, he started crying and saying that no one had ever thanked him before,” she recalled.

Olson, 33, set out to convince her company that making Veterans Day cards was a good idea. The company had found out otherwise in tests of the cards in 1985 and 1999, when sales proved sparse.

Hallmark agreed to give it another try, and a team of writers and artists volunteered to help with designs, along with their normal duties.

The team expected about 5,000 stores would want the cards when they became available earlier this year, according to Hallmark spokeswoman Rachel Bolton. Instead, orders came in from more than 18,000 stores, and some have already ordered a second batch.

Hallmark Cards Inc. is finding success with a line of Veterans Day greeting cards. The company test-marketed the cards with lackluster response in 1985 and 1999, but the Sept. 11 terrorist attacks have created new demand, according to company officials.

While precise information on sales is not yet available, Bolton said of Olson, “Sales have proved she was right.”

The difference between this year and the earlier experiments is obvious, Bolton said. “Things had changed,” she said. “People were feeling different following 9-11.”

Most of the 20 Veterans Day cards in Hallmark’s line are aimed at specific groups of veterans. There are cards for each branch of the military, for veterans of World War II and the Korean, Vietnam and Persian Gulf wars, for women, for fathers and for sons.

Last year, Hallmark’s biggest competitor, American Greetings, offered some cards for Veterans Day in conjunction with other patriotic cards issued after the terrorist attacks. This year, it is offering electronic Veterans Day cards on its Web sites, www.americangreetings.com and www.bluemountain.com.

Bolton said Hallmark’s top-selling card so far is one for fathers that features two children with their hands over their hearts. It reads: “Thanks for Defending ‘Liberty and Justice for All.”‘

Hallmark has a production facility in Lawrence that employs 830 workers.