The project that Philadelphia stained-glass artist Judith Schaechter proposed to Eastern State Penitentiary in June 2010: To fill the skylights of its moldering prison cells with a series of stained-glass windows. Period. It offered none of the usual pedantry that Sean Kelley, Eastern State's director of programming, and his committee had come to expect in artists' proposals since launching the penitentiary's exhibition program in 1995.

"We had discussed her work in the past, saying that it would be ideal for the space, but it was still a hard decision to accept her proposal," Kelley says. "It's rare for us to accept a proposal without a very specific idea of what the artist will do." Nevertheless, Kelley, who has final say on each year's projects, gave Schaechter the green light.

Asked precisely what she pitched to Eastern State, Schaechter, no shrinking violet, doesn't miss a beat. "I knew there would be a lot of lag time and I wanted my project to be fresh," she says, with an unapologetic shrug. "I work very intuitively and I start with an idea that may end up completely different. So I just promised stained-glass windows."

The fact that Schaechter, trained at the Rhode Island School of Design, was both a Pew and a Guggenheim fellow couldn't have hurt her prospects, as she herself acknowledges. "I think my reputation preceded me," she says, slowing her typically enthusiastic, staccato speech to a mock-conspiratorial tone.

Two years later, she has made good on her promise. The prison has the 17 exquisite and mostly elegiac stained-glass windows that make up Schaechter's project "The Battle of Carnival and Lent," and they've been expertly installed by Bryan Willette, a friend who played with her in a punk band (yes, she did that, too) and is a stained-glass artist himself. The windows make their public debut Sunday.

"The Battle of Carnival and Lent" takes its title from Schaechter's largest window, which fills an arched transom in the hallway of cell block 11 like a window at the 12th-century cathedral in Chartres. It's her nod to stained glass' ecclesiastical roots, she says, although she did not care for religious-themed stained glass as a younger artist.

"I grew to appreciate it on its own terms, but it was decades in the making," she sighs. "When I started making stained glass I was much more arrogant than I am now. I know I wanted to take it into the 21st century."

The rambunctious, jewel-colored scene it depicts was inspired by Pieter Breughel the Younger's painting of almost the same name (his is The Battle Between Carnival and Lent, and is itself a copy of the painting The Fight Between Carnival and Lent by his father, Pieter Breugel the Elder).

"It seemed very appropriate to ESP as it's about the angel-versus-devil battle that all who have control issues are contending with," she says. In her version, monks, representing Lent, clash with clowns, their party-animal opponents, in a riot as reminiscent of a contemporary flash mob as of a scene in 16th-century Antwerp.

"It's kind of a play battle," she says. "There's no serious damage being done here."

In cell block 8, for which Schaechter created 10 narrow skylight windows for five cells, she decided to reference birds and weather.

"I tried to empathize with what it would be like to be a prisoner, and I imagined that birds and the weather would be a huge entertainment," she says. Her subjects are Prometheus, "who had his liver pecked out by a bird every night"; Atlas - "he's the one in the wind, carrying a burden, like everyone"; and Andromeda, "who has for centuries been an excuse for artists to make soft-core porn - I wanted to make her a feminist heroine." It's hard not to wonder what the incarcerated of the past would have made of Schaechter's dark humor.

Cell block 8 also features two windows on themes from the Bible, which might as well have been mythological to Schaechter, 51, who was raised in Newton Center, Mass., by agnostic parents ("my father is a Russian Jew by way of Italy and Ecuador, my mother was an Episcopalian from Kansas," she says).

"One is Mary Magdalen, who is basically my favorite character in the Bible, and she's in a window that depicts a window in a cell at Eastern State with the reflection in the sky making bars on her body, and the other is Noah, who was told by a bird that the flood was over. "

Weeping women, the defining figures of a Greek tragedy's chorus, are the theme of cell block 14's three skylight windows. "I decided specifically to make a mother, a sister, and a daughter. They are those left behind to deal with the wreckage after someone is sent to prison," Schaechter says.

Cell block 11 features three windows based on the myth of Icarus in one cell and the transom at the end of the hallway where "The Battle of Carnival and Lent" is installed.

"The myth of Icarus always bothered me because Icarus is punished for his hubris in wanting to fly near the sun," Schaechter says. "It all sounded awesome to me. Like why would you punish someone for dreaming big? I have a lot of sympathy for Icarus." In Schaechter's rendition of the theme, one window shows birds, one is of a man superimposed on a bird, and one is a hand pointing at a wing dripping with wax.

But Schaechter's large transom window is far and away the main event of her project. "It's the second-largest window I've ever made, and it's by far the most complicated one. It has 96 figures, and I'm counting things like snails. It was important to me to make it a masterpiece. Talk about hubris and being punished by the gods! But I decided to go for it."