By Carol Glatz | Catholic News Service

VATICAN CITY -- What the general public can squint at and admire from afar, an art restorer can enjoy from just inches away.

Perched on scaffolding and cleaning off centuries of soot under bright directional lights, the restorers' privileged peek doesn't come often or easily. Full-scale restoration projects are expensive and complex, happening in some instances every 100 years, like the project underway at Rome's Sanctuary of the Holy Stairs.

With the help of private donors and the Patrons of the Arts in the Vatican Museums, the Vatican Museums have been overseeing a 15-year-long restoration of the sanctuary, which houses stairs that, according to tradition, are the ones Jesus climbed when Pontius Pilate brought him before the crowd and handed him over to be crucified.

Pope Sixtus V ordered the building of sanctuary during his brief pontificate at the end of the 16th century.

He employed more than 40 painters who spent two years covering 18,300 square feet of high walls and vaulted ceilings with decorative paintings and frescoes depicting Christ's passion, biblical events of the Old Testament and larger-than-life-sized images of saints and doctors of the church.

The sanctuary was restored at least three times before: in the 1700s, the 1800s and the 1930s, Laura Ugolini, one of the restorers, told Catholic News Service.

With the latest cleansing, restorers are discovering stunning, hard-to-see details and uncovering hidden frescoes.

When masons recently drilled through a gray wall to run an electric cable for updated lighting fixtures, they noticed different colors of dust spilling from the drill hole -- a sign that a painting, not just plain wall, was underneath.

The restorers did a quick scrub of two random sections, and to everyone's surprise, they found a frescoed hand and a face. "Nobody thought this would be here," Ugolini said.

Renaissance painters could be playful, she said. For example, the walls are bordered with decorative patterns of the symbols of Pope Sixtus: the Marian eight-pointed star, pears -- representing his family name "Peretti" or "little pears" -- and a lion.

Perhaps playing a game of "Which one doesn't belong," an artist portrayed one of the golden lions as distracted; instead of facing the stairwell straight on like the hundreds of lions around him, his majestic mane is coyly turned to a 3/4 profile.

Restorers uncovered the year "1589" painted in faded black brush strokes high in a corner out of sight to mark the year the painters began their work on the vault and the last names of Vatican restorers "Mizzoni-Grossi" printed in thick pencil, along with the note "restored in the year 1937-38."

Mary Angela Schroth, who is coordinating the Holy Stairs project, said a coded signature was found in one chapel: a small pair of spectacles etched into the plaster -- representing the mark of one of the sanctuary's painters, Flemish Renaissance master Paul Brill, whose last name in Flemish means glasses.

"These are truly moving moments for us," Ugolini said, because it is "like entering into direct contact with the craftsman."

Every time the restorers wipe away the dirt and grime, it leads to another "emotional moment because you find telltale marks like indents from hand-support sticks used by the painter, and in certain cases you even find fingernail marks dug into the fresh plaster," she said.

"The feeling you get from touching a work of art that is so important in the world is a huge thrill," she added.

But the best part about their high-rise view, the restorers said, is seeing Brill's masterpieces clean and up close.

Brill was used to doing oil paintings that were hung at eye level, Ugolini said.

Even though he learned the fresco technique when he came to Rome, "he still painted as if it were a painting with small details and tiny brush strokes," she said, and not simple scenes with bold chromatic colors and large statuesque characters that are easier to see from below.

In Brill's ceiling scene of Jonah and the whale, the raging yellow eye of the frescoed sea beast, its viper-like fangs, the ship's sails snapping in the wind and the crew's anxious faces while sheep and goats peacefully graze on a rocky shore all are likely to be a blur and impossible to appreciate when descending a dim staircase.

Ugolini said that with so many individual restorers working piecemeal on small patches, they are never sure how uniform or striking the final result will be.

However, she said, that means the restorers get a second revelation when the scaffolding is dismantled and they can "finally admire the frescoes from the correct distance."

"This is a teaching sanctuary," Schroth said; the frescoed scenes are meant to guide pilgrims from the early foundations of the faith in God to the mystery and glory of Christ's passion, death and resurrection.

"But if the sanctuary is dirty, if the frescoes can't be seen," she said, "if there's no light, how can the faithful proceed on their spiritual destination at the sanctuary?"

Restoring the original splendor of the Holy Stairs sanctuary is, Schroth said, "a story of resurrection" -- a story of encountering fragility and offering new life.