Parents at River Hill High School in Howard County are being urged to look a little more closely at their children's report cards.

Starting this month, quarterly grades will be printed on paper that bears a watermark resembling a globe -- similar to the kind found on new $20 bills -- that is visible only when held up to light.

In an e-mail, Principal William Ryan told parents that no one incident prompted the move but that school officials hoped it would deter students from trying to replicate an authentic report card with a little computer wizardry.

The school's PTA president, Angela Ballard-Landers, said: "It's just a proactive approach we're taking to eliminate the possibility. Almost like what banks use in terms of checks so there won't be any fraud."

The watermarked paper, which Ryan said costs several hundred dollars a year, is one example of the increasingly sophisticated methods teachers and administrators across the country are using to prevent potential cheating by today's tech-savvy students.

Several years ago, high school principals in Howard County agreed to start printing report cards on paper bearing a latent image, such as the school's name or the word "void," which appears only when it is photocopied or scanned, said David Bruzga, the school system's director of secondary school instruction. To the naked eye, the paper appeared no different from the kind on sale in bulk at office supply stores.

"There have probably been some bright little minds that have been [changing their report cards] for decades," said Scott Pfeiffer, a former principal of River Hill. "But now the technology is such that we can take some reasonable steps to make that less likely."

In a 2000-01 study of high school students by Rutgers University Professor Donald L. McCabe, who founded the nonprofit Center for Academic Integrity, 74 percent said they had cheated at least once on a test. Seventy-two percent said they had cheated on a written assignment.

The motives for cheating are the same as they have always been, including fear of getting grounded by a parent, administrators and experts said. It's the methods that are new.

Students "will use the technology available to them," said Mike Adams, a board member of the Center for Academic Integrity and a high school principal. This Internet-wired generation can buy term papers online, text-message test answers to friends using cell phones and turn Palm Pilots into modern-day crib sheets.

So this year, River Hill decided to make faking a report card harder. The new paper is available only from Ohio-based company Scrip-Safe and is created and stored in a secure plant.

The company's president, Joe Orndorff, said Scrip-Safe has contracts with about 1,800 colleges and about 300 high schools nationwide and provides paper for such things as transcripts and hall passes.

When the paper is held up to light, watermarks that look like globes appear on both sides, Orndorff said. The ink in the latent image shows up in every type of photocopier, he said. The company also offers the option, mostly used by universities, of imprinting a signature of a school official on the paper so that it is distorted or disappears entirely when copied.

"Kids today, with the computer, they can make something look pretty much like what the report card looks like," Orndorff said. "We add the security features that a student could not add to the report card."

Ryan said printing report cards on the paper helps prove to parents that their children's grades are valid and also helps assure colleges and universities that student transcripts are authentic.

River Hill is one of Howard County's highest-performing schools. It has the second-highest average SAT score in Howard, and the pressure to excel can be great.

"We do have a very competitive school with transcripts going to some of the most competitive colleges, and we want to make sure that all of that going out is official and representing the school," Ryan said.