dust sheet 
noun British
A large sheet for covering furniture or flooring to protect it from dust or while decorating.In January 2002 she tripped on a dust sheet left by decorators breaking her hip....
- His desk did not look convincing, and rather than a portrait of Riccardo, to which he directs part of his aria, there was a bronze statue, lying under a dust sheet on a paint-spattered trestle table, which made no sense at all.
- It is said one of the builders walked on to scaffolding wearing a white dust sheet as a joke.