I start with a window film kit. 7’x9.3’. 1.5 mil thick (instead of the .7 mil lighter weight).
This type even has one edge pre-taped.
Double sided tape and nylon washers.
Place the washer on the double sided tape and then fold over. Repeat for each edge.
Then tape the corner down with a fold of transparent gorilla tape to reinforce it.
Then you have four corners.
Then make a hole. Use a hot metal skewer or a drill.
Then you have a tarp. This one is pretty large.
Ready to fold up and store in a zip lock bag.
About eight ounces. Smaller tarp or less tape would weigh less.
Usually I deal with a 5’x7’ tarp or 35 square feet. 7’x9’ is around 63 square feet—so twice as large .
The pre-taped edge added an ounce or so to the weight over what the alternative would weigh.
So I’d seriously consider using a different base or trimming the pre-taped area off if I were doing this again.
You can also save weight by making it slightly smaller.