An overcover is a solid fabric covering that fits over the top of your hammock. It’s much like the insect netting, but with fabric. It normally has a vented section made with a more breathable noseeum netting in order to help prevent moisture buildup and condensation inside the hammock.
An overcover can really be enhance your hammock camping experience by allowing you to camp more comfortably in colder weather. It works by blocking or slowing airflow that robs heat from your insulation. A properly vented overcover can add 10-15 degrees inside your hammock, depending on the conditions. It also blocks wind and moisture that finds its way under your tarp. Some people also use it for added privacy while changing and darkening the hammock when snoozing during the day.
Keep in mind that an overcover must be ventilated properly to avoid building up condensation inside your hammock. Often the built-in mesh vent will provide enough airflow to avoid moisture, but other times it will be necessary to open up one or more zippers to provide add’l airflow.
Note: When building an overcover from the Monolite Ripstop Nylon Mesh we do not add a vent. Basically this fabric is breathable enough that the whole thing acts as a vent.