How should sprinklers subject to overspray accumulation be protected?

To protect sprinklers that are subject to overspray accumulation, using a thin paper bag is effective because it allows for adequate air circulation while preventing debris from settling on the sprinkler's surface. This is crucial because any obstruction can impair the sprinkler’s ability to operate effectively when needed. The thin material of the bag generally does not hinder the sprinkler's activation and can easily be removed without damaging the sprinkler itself.

The other options, while they provide some form of protection, may not be as effective. A plastic cover can trap heat, which could potentially lead to unintended activation of the sprinkler system. A metal guard, while durable, could obstruct water flow or impact the spray pattern. A rubber sleeve may protect the sprinkler, but it can also restrict air circulation, which is important to prevent buildup that could affect functionality. Thus, the choice of a thin paper bag balances protection with the essential need for the sprinkler to remain operational and unobstructed.