You wake up at 3 a.m. with a burning need to buy paper clips and one of those dry-erase markers that you can wipe off with a rag. You need it right now.

And in this 24-hour city, you’re in luck. Welcome to the home of 24-hour office supplies.

There are two Staples stores in L.A. County, and a total of 15 around the country, that are open around the clock part of a test to determine whether an all-night operation pencils out for the chain.

But who on Earth buys office supplies at 2 in the morning?

“You’d be surprised,” said Jim Peters, president of U.S. stores for Westboro, Mass.-based Staples Inc. “The thought came to us from our Internet business when we started noticing that people were ordering their supplies at all hours of the night. It doesn’t work in all markets, but ones in metropolitan, highly dense locations and near universities.”

Like the 24-hour Staples at Bundy Drive and Olympic Boulevard in West L.A., where a reporter monitored the comings and goings one recent morning starting at 3:45 a.m.

As with all-night supermarkets, drug stores and coffee shops, the pace is well, let’s call it leisurely.

As a security guard sat in a chair eyeing his watch, no one was manning the six cash registers or copy service center. In fact, there were no customers. The only noise in the place came from piped-in music and a few employees unloading boxes in one of the aisles.

At 4 a.m., three customers trickled in. This is what constituted the early-morning rush.

Somewhat frantic, marketing consultant Mike Rotenberg needed to make copies for a 9 a.m. meeting with an animation studio planning to launch a Web site. He was running much later than anticipated due to a virus that tied up his home computer for most of the night.

“Is somebody working back here?” Rotenberg asked the guard about the copy service center.

“I’ll call someone up here,” replied the guard, reaching for the wall phone.

As Rotenberg waits for a sales associate, he explains what drives him to work into the wee hours.

“This is in line with business today. It’s a necessity. In my business, new media, companies need everything now. I’m tired. I’m rambling,” said Rotenberg, 38. “Being self-employed, your hours aren’t 9 to 5 and you don’t have the resources of a big company. I don’t have an (information services) department or someone who I can say, ‘Make me 10 copies of this’ to.”

While he waited for his copies, another customer, Stan Zlobecki, 33, was trying to return items that he had already exchanged for products that he had earlier bought at another Staples.

Zlobecki, who used his store credit to purchase $100 worth of replacement film for fax machines and compressed air dusters, was on his way to Hawthorne to drop off the merchandise.

“It works out. I run errands for my computer friends. They might pay me $10 to $30 for picking up these supplies that they don’t have time to get,” said Zlobecki, who restores cars during the day.

Meanwhile, Ernest Lapec, 22, stood at the electronics counter waiting to exchange his cordless phone, which didn’t work. Lapec works the night shift at a nearby manufacturing facility.

“I just come here after work and get my errands done. It’s like I’ve got the whole place to myself. It’s great,” he said.

Customers aren’t the only ones who feel like they have the place to themselves in the early-morning hours. So do the employees, who use the time mainly to get the store organized because there are so few customers to serve.

“It’s really convenient for us and our customers. Lots of our products come in the evening, so we’re here to stock them and have full shelves for our daytime customers,” said late-shift manager Matthew Mataalii, a five-year employee.

Mataalii was not required to work the graveyard shift he volunteered. It allows him to work two jobs; during the day, he is a teacher’s aide at a public elementary school in Hollywood. He said he catches a few hours of sleep in between shifts.

What are customers looking for in the middle of the night? It’s seldom the big-ticket items like computers, electronic equipment or office furniture, says Mataalii (though a woman did come in a few days earlier at 2 in the morning to buy a laptop computer, a printer and a fax machine). Rather, they tend to be folks like Rotenberg who are working on business projects and need supplies or copies. Or they’re college students pulling all-nighters, or late-shift workers like Lapec.

Though Peters declined to comment on the cost of being open all night, he said Staples instituted only slight changes, including increasing night-time staffing by 30 percent.

“The cost is minimal,” he said. “It’s similar to a grocery store mentality. You have people stocking the shelves at night anyway and the lights are on, so we just decided to open our doors to our customers.” Previously, the store was open during the week from 7 a.m. to 9 p.m.

The Bundy store was one of four outlets that started experimenting with all-night opening hours two months ago. Year to date, sales at the location are up 15 percent over last year, according to General Manager Alex Ang, who attributes 5 percent of the growth to the new hours.

“We see mostly younger men and women who come in,” said Mataalii. “They seem to be less stressed, unless they’re coming in because their printer ran out of toner.”

Mark Collins fits the profile. Arriving at the store at 4:30 a.m., he was looking to pick up a black binder notebook, a box of envelopes and ink-jet printer paper.

For the full-time UCLA student and computer analyst, shopping in the very early morning is a regular activity.

“It’s my favorite time to shop. I won’t come here during the day with traffic, parking hassles and long lines. I hate dealing with crowds, and this is on my way home after work,” said Collins, 33, who was winding down from his 5 p.m. to 2 a.m. work shift in Santa Monica.

Around 5:45 a.m., customers are looking less bleary-eyed. On his way to work as general manager of a Hamburger Hamlet restaurant, Ken Kofman dropped by to buy fax paper, pens and paper clips.

“I’d much rather do this at the beginning of the day, rather than the end,” said the 45-year-old Kofman.

By 6 a.m., the security guard puts on his jacket and exits. Maatalli bids him “Good night. Good morning.”