I've used Tyvek, space blanket, contractor bag, and a 5'x5' tarp. I've been carrying the tarp more because it can double as a small windbreaker or shelter in an emergency.
I’m not a fan of using my shelter tarp for a meat tarp. I classify my shelter tarp as a critical piece of gear. Which means I have to get it clean , dried off and back into my pack before I go back to the field. I normally use either contractor bags or a piece of painters plastic so I can just throw it away. I replace my used kill kit with my second kill kit so I don’t have to wait to clean my game bags before I go back out.