Tarp is indispensable to protect you from the rain. Sure, it’s wonderful to hammock under starry skies, but we live in Sweden and the weather will be accordingly. A tarp makes life easier. At least hammock life.
Bushmen’s thermo pair has a reflective / insulating inside. DD Hammock’s tarps are affordable wear wolves. Their super light series is a little more fragile but still good tarps. Dutchware’s tarps are of high quality (like everything else they do).