“Sometimes a ring appears after spot cleaning my carpet. How can I prevent this from occurring?”

John’s Answer:

First of all, regardless of whether you are able to completely remove your spot, always be sure to follow up our spot cleaner with a fresh water rinse. This will remove the chemical residue.
Here’s a trick that will help yield even better results. While the spot is still damp from the rinse water, lay a clean terry cloth towel over the spot and place a heavy object on top of that (a phone book will do) and leave it there for 24 hours.

The wicking action that caused the ring to form on the tips of the fibers will instead migrate up into the towel. I think you’ll be impressed with the results.