ROME — Restorers on Tuesday put the finishing touches on a seven-year restoration of two underground burial rooms at the Catacombs of Domitilla, which revealed long-hidden frescoes commissioned some 1600 years ago by the city’s bakers.

“We finished working on one cycle practically this morning,” said Barbara Mazzei, who oversaw the restoration of the paintings on behalf of the Vatican’s Pontifical Commission for Sacred Archaeology.

The frescoes had been hidden under a chalky deposit and algae during their many centuries of abandonment, while smoke from oil lamps had darkened the crusty surfaces. Using lasers, restorers stripped away the deposits strata by strata — a technique never used before in the catacombs. A mélange of figures gradually emerged, depicting Old and New Testament figures, but also vignettes relating to the baker’s trade.