Stain Removal: Pet Urine, Coffee & Ink

Three Very Difficult Stains

Throughout the stain removal process, Fiber-Seal Service Centers see all types of stains and soils when helping our customers maintain the appearance of their floor coverings and above-the-floor fabrics. We run into unusual problems from time to time, but for the purpose of this article, we have chosen to discuss three very common (and very difficult) stains: pet urine, coffee and ink.

Note: This article will focus on the nature of these staining materials, describing why these stains are considered more difficult than most. We will not describe specific removal methods since in most cases removal of these stains should be left to the professionals.

Pet Urine

Urine is one of the most difficult stain removals to perform in interior environments. The yellow compounds in the urine tend to act as dyes. They attach to the dye sites of a wide variety of fibers with surprising tenacity.

Fresh urine stains are slightly acidic. As the urine ages, it begins to break down into other chemicals, including ammonia. Ammonia readily combines with water vapor from the air to form ammonium hydroxide, a very alkaline substance. This alkalinity can create dye bleeding and fiber damage, especially on wool fibers.

Another aspect that needs to be considered is the volume of the stain. While it may look to be a small urine stain on the surface of a carpet or rug, it is likely to be 3 to 4 times the size underneath in the backing and padding. In many cases the urine can penetrate all the way to the sub-flooring, making removal even more complicated.

The bottom line is to remove as much as possible as soon as possible. Professionals should be consulted for help with pet stains, since they have the resources to confront most of the associated problems. However unless the pet is restricted or house-trained properly, the problems
will continue to get worse, eventually causing irreversible damage.



Many years ago, coffee was used as a dye. In addition to being an excellent dye-type substance, coffee is often hot when it is spilled. Heat opens up dye sites on fibers and allows a deeper, more rapid attachment of the coffee.

Complicating matters are the wide array of coffees and the chemicals (sweeteners, cream, etc.) that are sometimes added. Combined these with the wide array of fibers and fabrics and you have a recipe for problems.

Timely blotting of spills is beneficial, but not always enough. Neutral or slightly acidic detergents can go a long way in helping to remove coffee. Professionals have access to industrial strength detergents, but even these cannot always remove the last traces of the coffee. On some sensitive fabrics, complete success may be impossible.


There are, of course, dozens of different types of ink. Some are water-based and many are solvent-based. There is one common factor: most inks are intended to be somewhat permanent. Also, the larger the ink stain, the more difficult is the removal.

The misguided swipe of a pen is not the worst thing that can happen to a fabric. With a little professional care, this type of stain can often be removed even from delicate fabrics. Most of the real problems come from a broken pen that has seeped into a cushion or floor covering or a heavy-handed child that didn’t know it was not okay to write on fabric. Removal attempts can often lead to the spreading of the ink, or what we call the “blossoming” of the ink. The untrained professional can take what appears to be a small ink spot and turn it into a sea of blue.

Fiber type is also a factor, as it is with most spot removal techniques. Professionals should only handle ink spots. Many home remedies (hair spray or milk) that seem harmless can create more problems or damaging effects.

Some inks spots may never be 100% correctable because of the ink type, fabric type, or sheer quantity of ink. The professional knows when to stop trying.

Fiber-Seal Efforts

Focusing on the care of high-end interior furnishings, including plush floor coverings, Fiber-Seal Service Centers have seen their share of unexplained pile reversal complaints over the years. While we do not claim to be able to correct these problems, we continue to document them for further study.

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