What is the best thing to use to hold down the corners of an area rug?

Question

I have a new area rug on top of my existing carpet. I need something reliable that will keep the corners/edges from lifting. Where ( on-line prefferably) can I buy something that WONT damage my existing carpet or new carpet?

Answer 1

You can purchase double backed carpet tape at any hardware store, on line or in person.

Answer 2

glue heavy magnets to the bottom corners