fres·co 
(frĕskō)
(frĕskō)n. pl. fres·coes or fres·cos
1. The art of painting on fresh, moist plaster with pigments dissolved in water.
2. A painting executed in this way.
tr.v. fres·coed, fres·co·ing, fres·coes
To paint in fresco.
[Italian, fresh (plaster), of Germanic origin.]
fresco·er, fresco·ist n.