Kleenex

Kleenex is a brand name for a variety of paper-based products such as facial tissue, bathroom tissue, paper towels, tampons, and diapers. Often used informally as a genericized trademark for facial tissue in the United States, the name "Kleenex" is a registered trademark of Kimberly-Clark Worldwide, Inc. Kleenex products are manufactured in 30 countries and sold in more than 170 countries. Kleenex brands include Cottonelle, Huggies, and VIVA. 
History.
Kleenex began during the First World War. It developed a crepe paper used as a filter for gas masks. In the early 1920s, it was adapted as a consumer product called Kotex brand to help women with their periods.
The first Western facial tissue was introduced in 1924 and originally marketed as a way to remove cold cream (it had already been in use in Japan for centuries; see History of facial tissue for details). It was a disposable substitute for face towels or cotton wool. In 1925, the first Kleenex tissue ad was used in magazines showing "the new secret of keeping a pretty skin as used by famous movie stars." A few years after the introduction of Kleenex, the company's head researcher tried to persuade the head of advertising to try to market the tissue for colds and hay fever. The administrator declined the idea but then committed a small amount of ad space to mention of using Kleenex tissue as a handkerchief. By the 1930s, Kleenex was being marketed with the slogan "Don’t Carry a Cold in Your Pocket" and its use as a disposable handkerchief replacement became predominant. In 1943, Kleenex began licensing the Little Lulu cartoon character to popularize the brand.
Kleenex trademark.
The original Kleenex trademark application at the United States Patent and Trademark Office (USPTO) was filed in the class of Medical, Beauty, & Agricultural Services by Cellucotton Products Company of Neenah, Wisconsin, on Saturday, July 12, 1924. The description provided to the USPTO was "absorbent pads or sheets for removing cold cream."
The first use for the drawing and stylized word mark in commerce was on June 12, 1924. USPTO granted trademark registration on November 25, 1924. International Cellucotton Products Company officially assigned trademark interest and good will of the business to Kimberly-Clark Corporation on September 30, 1955. Kimberly-Clark Corporation of Neenah, Wisconsin is the current registered owner of the Kleenex trademark.
In the US, the Kleenex name has become—in common usage but "not" in law—genericized: the popularity of the product has led to the use of its name to refer to any facial tissue, regardless of the brand. Many dictionaries, including Merriam-Webster and Oxford, now include definitions in their publications defining it as such.