Jute sacks are made from Corchorus olitorius or from Corchorus capsularis. But sometimes they are made from coconut fibers but marketed as Jute sacks.
It is a brown colored wooven sack with big gaps in between the threads. Sometimes they are sold as rolls in Home Depot. They are often used to control erosion. Sometimes I see construction companies here take a whole roll and blockade it against the sewers to prevent soil from getting into them during construction. Sometimes CalTrans would put them over the supporting soil of a newly constructed ramp while the trees are growing. It is biodegradable but long lasting like 5 years or more, so ideal for those application.
So much for the lecture...
You buy a large tomato wire cage (round conical shape), put it over your paw-paw seedlings. Then cut the bottom hole of the jute sack and place over the paw-paw seedlings. This would block about 60-75% of the sunlight that would simulate shade to establish your paw-paw much quicker.
This means that you are not limited to using Jute sacks, you can use other shade cloth or material that will provide 60-75% shade. Jute sacks are the cheapest to use if you can find them, but if no one is using them in your area, chances are when you do find them, they would be expensive.