Silk thread and cloth
If the moths were allowed to emerge from the cocoons, they would make holes in the silk thread. The silkworm farmers kill the pupas inside the cocoons by baking them in a hot oven. Then they soak the cocoons in boiling water to loosen the threads. A person finds the end of the thread and places it on a winding bobbin. Then a machine unrolls the cocoon, winding the silk from five cocoons together to make one silk thread. Then the thread is woven into cloth. You can make thread yourself. Learn how in the Teacher Resources section.
It is interesting to note that one ounce of silkworm eggs contains 40,000 eggs (1,500 eggs per gram). These worms will eat 3,500 pounds (1500 kilograms) of mulberry leaves, and will spin cocoons which will produce 18 pounds (8 kilograms) of silk thread. It takes 1700 to 2000 cocoons to make one silk dress (or about 1,000 cocoons for a silk shirt).
This internet resource has an excellent overview of silk and how the thread
and cloth is made.