Finding suitable paint to use on old lime plaster is easier said than done...

Zinsser Grade 1 is a self-priming finish for interior walls and ceilings of traditional and historic buildings; effectively covering unsightly stains.
Zinsser Grade 1 is a high performance, self-priming finish for the interior decoration of walls and ceilings in traditional and historic buildings, including churches, castles and period properties, developed with a high solids formula that works to effectively block unsightly stains caused by nicotine, graffiti, water, fire and smoke.