Behind the scenes of the Hollywood blood business

Season five of the hit AMC series "The Walking Dead" premiered Sunday night and fans of the undead got a fresh dose of zombie love.

An estimated 17 million people tuned in, shattering last year's record for a basic cable show.

Now, the zombie apocalypse is part of a bigger trend bringing more gore to TV screens than ever, reports CBS News contributor Lee Woodruff.

"We've been in business for 25 years," said special effects wiz and co-executive producer Greg Nicotero. "'The Walking Dead' probably uses up the most amount of blood that we've ever had on any show. I would say per episode, we're usually somewhere in the 20 to 30 gallons range."

Nicotero and his crew make every bit of that blood -- along with all sorts of ghoulish figures and dismembered body parts. All of it fake, but made to look very real.

The blood recipe and its appearance changes depending on how it's going to be used in a scene.

"We have a different variety of blood," Nicotero said. "We have dark zombie blood, we have dried blood , we have coagulated blood. If you have a shirt like my shirt which is dark, and you want to see the blood on it, it has to be brighter, otherwise it would just fade in with the color."

He assured it's not just a bloody mess.

"It's kind of -- oddly -- a weird art form," Nicotero said.

Television has gotten into the blood business in a big way.

Time was, the horror genre on the small screen was handled with comedy -- like "The Munsters" and "The Addams Family" -- or in a campy way like the vampire-based soap opera, "Dark Shadows." Nary a drop of the red stuff to be seen.

Today, with vampire and zombie shows cram-packing television schedules, blood will -- and does -- flow.

Entertainment Weekly editor at large Dalton Ross said he thinks the increase in blood in blood and gore on TV is a natural progression.

"Cable is responsible," he said. "You know, once cable TV comes to the forefront there are so many more options with less restrictions. So you're gonna see more violent fare."

He said gruesome blood and gore is big business in Hollywood right now.

"Television is a copycat industry," Ross said. "As soon as you have one or two shows that are a little extreme, that show a little blood, that are doing-- start to do very well, well guess what? Everyone wants in on it now."

But one special effects master said he hasn't seen this much blood and gore on TV in his lifetime.

"Now that we are able to create effects faster, and better for television, we're really allowing the producers and the writers to do whatever they want," "True Blood" special effects artist Todd Masters said. "Whereas, before, they were limited either to the -- you know, the big-budget feature films, or just to kind of, you know, keep it limited to a cutaway, or a shadow on the wall, or something."

So if blood sucking or the undead is your thing -- now is your moment in the sun -- or in the dark as the case may be.