I have not yet made copper soft jaws for my 4 jaw 4" lathe chuck.
Did not want to take the time to make them today.
On hand was a bunch of .003 shim stock.
Cut a piece just wide enough to cover the chuck jaws.
Cut it to a length that is about 1/8 to 1/4 inch shorter than the circumference of the part that needs protection.
Position it inside the chuck jaws and insert the part to be turned.
Works every time. Save it in a little box for later use and add others as the need arises.