When cleaning carpets and furniture or when removing spots, we are often told to first test the cleaning solution "in an inconspicuous area." However, we are rarely told exactly how to conduct this test. And even if we do "wing it," exactly what are we looking for?
To help cleaning professionals better understand this process, we turn to industry veteran Sara Thurston with Nilfisk, makers of professional cleaning equipment and manufacturers of the U.S. Products line of portable extractors.

But first, Thurston says we must be clear why this test is necessary.
"Some cleaning solutions can damage fabrics and carpet fibers, changing the color or the ways the fabric or fibers look. Further, some carpet and furniture in residential and commercial settings are made of a combination of fabrics and fibers. A cleaning solution may be safe for one fiber but not another."
With that explained, this is how Thurston suggests we safely test a cleaning solution on a fabric:
Identify an inconspicuous area. An inconspicuous area on a chair or sofa would be the backside of the furniture's "skirt" or the underside of a sofa or chair. For a carpet, it would be a corner area, behind a door, etc.
Dampen a terry cloth towel with cool water.
Apply a small amount of the cleaning solution to the damp towel. If the product is to be diluted before using, properly diluted it as instructed by the manufacturer.
Blot-do not rub-the towel (with solution) on the inconspicuous area.
If the color starts to bleed, transfer to the towel, darken, lighten, or change in any noticeable way, stop the test; this likely is not the right cleaning solution for this fabric.
If there are no changes, repeat the test using a little more cleaning solution.
"Now wait," says Thurston. "Sometimes it takes a few minutes to see how colorfast the fabric really is. To be on the safe side, if the material reacts in any way to the product, best not use it."