Originally Posted by
Candace
They protect the finish on the machine, so for that fact alone I use them. The spools rub the surface of the machine constantly and will leave permanent staining, mar the paint etc. so are a good idea.
This is definitely true! I have a 30's Singer I rescued from a thrift shop; it's in terrible shape and one of its (many) problems is a little half-moon worn into the finish where the thread spool spun for who-knows-how-many years!