A rare 16th Century Italian fresco has been restored to its original appearance after being painted over more than 150 years ago.
The Separation of Night and Day, painted by Guido Reni in 1599, will go on display at the National Trust's Kingston Lacy mansion, in Dorset.
Restorers have removed oil paint that was put over the work when removed from its original home in Italy.
Brought to the house in 1841, the fresco goes on display in the spring.
It was removed from Kingston Lacy, near Wimborne, earlier this year for the vital conservation work.
Restorers removed oil paint put over the work 150 years ago
Alan Bush, of the Bristol-based Bush and Berry Conservation Studio, said: "It became clear that the painting had suffered considerable damage at the time of its detachment from the ceiling of the Palazzo Zani in 1841.
"At this time, in order to remedy its poor condition, it was virtually repainted in oil paint.
"The adverse effect of this, apart from obliterating Reni's original work, was to have also masked the uniquely special quality of the fresco technique.
"It was therefore with great relief that, during the removal of the over-painting, we were successful in revealing the complete and original composition."
The work is due to be formally completed by Christmas and the fresco will return to Kingston Lacy in the first week of January.
It will go on display in the library later in 2006.