Miniatures is a big job. Just ask Mary Maclachlan and John Baster, who are supervisors for WETA Workshop's Miniatures Team.

"Making miniatures totally realistic and believable, and making them look like they've been lived in is the biggest challenge," Maclachlan says. "It can't look like a model when it's on camera."

Charged by Peter Jackson with creating intricate renderings for some of Middle-earth's most important settings, Maclachlan and Baster and their crew repeatedly rose to the challenge.

Especially when it came to developing Saruman's stronghold of Isengard.

"We threw away the rule book when we started on this film," Baster explains. "We had to develop a lot of techniques to get the look of the designs that we were working on, and a lot of the traditional model making methods were too slow or too rigid to capture the shapes and forms in the painting and drawings we were getting."

Those paintings and drawings served as the starting point for each model, and were furnished by famed "The Lord of the Rings" illustrators Alan Lee and John Howe, who worked closely with the miniatures makers.

"Alan and John were very interested to see their two-dimensional drawings become a three-dimensional reality, so they were very keen to come and see us," Maclachlan says. "They came down nearly every other day, and they'd do little sketches if a detail wasn't too clear on a bigger drawing."

"In the book you only see the bottom half of the tower at Isengard, but Alan conceptualized the rest of it with WETA," adds Baster. "They played around with different proportions of the tower, how thick it was at the bottom, and what sort of shapes are at the top."

The sketches were then sent to a draftsman, who turned them into actual blueprints for the miniatures crew.

"The small sculptural shapes and sizes were modeled out hard material and we then cast it into wax because the tower is supposed to be made from obsidian," Baster says. "The wax was carved with scalpel blades and given a shard-like feeling. Once all that componentry was done with the wax, it was reassembled into the final model material, and the tower was assembled."

Of course, that was just part of the job.

"We also had to build the ground around Orthanc for Isengard, and we built a wall that went all the way around it," Maclachlan says.

"They're actually 45 one-meter wall sections," Baster says. "We molded them in urethane and weathered them."

Then the miniatures team dug in-literally.

"We carved pits and holes into the ground before they did the shoot, and all the machinery and some of the pits we made were then lowered into the ground," Maclachlan says. "We pre-fabricated a few of them. They were like large cocoons, as tall as a person, and we did all of the little ledges inside, and we did all of the little machinery."

The details inside the Isengard caverns are a particular point of pride for their builders.

"There were little wheels, and lots of walkways and ladders and hammers and a lot of peculiar things which you can't imagine what they did," Maclachlan explains. "Most of the machines were made out of pine, or wood of one sort or another, and meshed together with what looked like metal strapping and rope--the way Orcs would roughly build things."

Baster considers some of the tower detailing to be a highlight of the set.

"The facade in some places has little windows, and within those windows are little rooms," he says. "We deliberately carved the whole exterior of the tower with scalpels, very neatly and at very small scale, and that catches the light and looks very sharp to the camera."

In all, the Isengard miniature set took up a substantial amount of space. The tower of Orthanc, built at a 1/35th scale, stood nearly 15 feet high. And the wall-to-wall measurement of the Isengard plain stretched 22 meters.

No wonder Maclachlan coined the term "bigatures" to describe these massive models.

"Whenever we would build a miniature that we couldn't get through the door, it became a bigature," she says.

"[WETA Workshop chief] Richard Taylor really likes to make the biggest, most detailed models that you can possibly build," Baster says. "That's where a lot of the realism is achieved."

Adds Maclachlan, "If the studio ceiling was any taller, we would've built the models taller, I'm sure of that. I had to get used to riding up and down the scissor lift and the cherry picker, which pretty much terrified me, because I'm not that fond of heights. But you got used to it."

And in the eyes of Maclachlan, Baster and their 10-person Isengard team, the hard work and attention to detail more than paid off.

"It's brilliant to feel that you are part of this incredibly creative team that's taken that small piece you've made and put it into the big picture," Maclachlan says. "And then to see it come to life with the actors and the digital backgrounds, the whole thing is stunning, it blows me away."