Proud manufacturer of high-quality natural fiber products

We specialize in the production of non-woven textiles and products of natural fibers. By selecting the best natural fibers and turning them into high-quality products, we have been one of the leading manufacturers of its kind in Europe for many decades.

With our knowledge and constant upgrading of existing technologies, we manufacture products that provide a higher level of usability and meet even the most demanding customers' needs.

Our products meet the highest quality standards. ISO 9001, ISO 14001, and OEKO-TEX 100 (Product class 1) certificates prove our commitment to quality and sustainable development.



The name KO-SI is present since 1970 when the company's designers identified a niche market and began processing natural fibers and animal hair for the needs of the automotive industry and manufacturing of upholstered furniture and mattresses. Over the years, we have constantly updated and developed our range of products.

Today's offer includes filling elements for mattresses and upholstered furniture, a horticulture program with erosion control for embankments and mats for plantations, protective packaging elements, natural insoles for shoes, thermal and sound insulation of coconut fibers for construction, air filters, and a program for domestic animals and pets.

We use carefully selected raw materials from renewable sources from renowned suppliers all around the world. These include coconut fiber, sisal, hemp, seaweed, jute, sheep wool, cashmere, horsehair, camel hair, natural latex, and lyocell.

We are present in more than 30 countries worldwide. With over 100 employees, we produce over 5 million square meters of various products per year and process over 9,000 tons of natural fibers exclusively for mattress manufacture.


Our team combines more than 100 employees in various fields.

Every individual counts.

Based on more than 50 years of experience, we create and provide top service and quality products that meet the highest standards and requirements.


In the development of new products, we rely on our own experience and long-term market presence. We strive to constantly deepen our technological knowledge and maintain long-term relationships with our business partners.

The development covers the entire process - from ideas, theoretical foundations, research, and measurements, to applications on accurate models. With the help of new technological processes, we develop new product lines or supplement the existing ones. In this way, we can generate broad and specialized knowledge and create optimal conditions to transfer knowledge into practice.

We strive to ensure that each product meets industry standards and specific ecological standards within the EU and the broader market in the development phase. With this, we want to ensure the product's competitiveness, quality, and the widest possible circle of customers, ensuring the company's existence and further expansion.


Our story dates back to the 19th century when Franz Pototschnig founds the TUS leather factory, the forerunner of today's company KO-SI.

Throughout history, the company faces many challenges and successfully overcomes many obstacles. Despite the challenges, the company constantly develops and introduces many new products.

KO-SI d.o.o., the successor of TUS, is today a modern and contemporary company with a long tradition and great hopes for the future.



Establishment of the TUS leather factory.
On the 1939 questionnaire, the industrialist and entrepreneur Franz Pototschnig mentions the year 1850 as the birth year of the leather factory. The factory remains family-owned up until 1945.
1914 - 1945
In both world wars, the factory operates for the army. During the interwar period, the factory produces drive belts, sole and haberdashery leather and shoe frames.
Post-war period
With the decision of the Slovenj Gradec-Šoštanj District Confiscation Commission and the Celje District Confiscation Commission, the Slovenj Gradec Leather Factory becomes the property of the general public property.
Introduction of rubberised horsehair
In addition to the regular production program, the TUS factory begins trial production of rubberised horsehair.
Serial production of rubberised horsehair
Successful attempts of rubberised horsehair production lead to the establishment of an independent plant for the serial production of rubberised horsehair boards. At the time, the company is the only producer of rubberised horsehair in the former Yugoslavia.
The 1960s
Presence on the Yugoslavian market
TUS produces rubber boards and felt from horsehair, coconut fiber, and straw. The company uses semi-finished products to manufacture mattresses and other upholstered products, protective helmets, pillows, seats for automobiles, and upholstered furniture for the furniture industry and resale on the Yugoslavian and European markets.
The first mention of the name KO-SI
Due to the growing demand for rubberized coir products, the TUS factory introduces a new plant named ko-si (kokos-sisal). The plant produces ko-si hats, protective helmets, and pillows. Rubberized coir is also in high demand in the furniture industry.
Internal reorganization of TUS
The growth of the TUS factory leads to the establishment of two autonomous organizations of united labor (TOZD NTU and TOZD UTEKS). Both TOZDs use plant fibers and animal hair for processing them into semi-finished products, protective equipment, and finished products intended for the automotive and furniture industries.
Establishment of TOZD KO-SI
The managers of the KO-SI plant decide to secede from TOZD UTEKS and form an independent plant with the processing of plant fibers into finished products as their primary activity. TOZD KO-SI and UTEKS coexist in the same production facilities.
Relocation of TOZD KO-SI
As sales and production of both companies in the same location are on the rise, TOZD KO-SI moves the production to a new location in Stari Trg where it can expand production and grow even further.
A year before the country's independence, KO-SI is one of the four autonomous organizational units of the social enterprise TUS. The other three units are UTEKS, PREVENT, and MIKON. Due to the political and economic changes in the country at the time, all four organizations transform to become independent companies.
Status transformation of the company TUS KO-SI o.sub.o. in TUS KO-SI d.d.
ISO 9001
Introduction of the ISO 9001 standard.
ISO 14001
Introduction of the ISO 14001 standard.
Relocation to the current location
In October 2011, the company KO-SI moves the headquarters and production to a new and modern building.
Expansion of Production
Due to increased workload, we carried out an expansion of our facilities into a new business building in 2018.
New Business Premises
Construction of new business premises is underway. We expect the premises to be completed in 2024.


  • ISPA - We regularly exhibit at the ISPA (International Sleep Products Association) fair
  • Interzum - We are a permanent exhibitor at the Interzum fair
  • Zelena Slovenija (Green Slovenia) - We are implementing our efforts for sustainable development and a humane environment in the membership of the Zeleno omrežje (Green Network)


As one of the leading companies in the field of plant fiber processing in Europe and a regionally important company, we are aware of our responsibility to the environment and the wider and wider community.

The basic guideline of the company is in the ecological orientation in the choice of raw materials and technologies as well as in the final products. In this way, we do not burden the environment and even after the end of the product's life, we ensure the possibility of recycling without expensive and complicated procedures.

We confirmed our orientation in 2004 by acquiring the ISO 14001 environmental management standard - which we regularly renew and take care of its consistent implementation.


We are aware that only products that fulfill the customers' expectations in all aspects bring success. By careful selection of raw materials and continuous optimization of the production process, we pay special attention to the quality of our products. We introduced the ISO 9001 (2002) and ISO 14001 (2004) standards for this exact purpose. Our insulation materials are tested and inspected according to DIN 4102-B2. Our final products bear the ÖKO TEX STANDARD 100 label, which ensures no traces of harmful or harmful substances in the products.
In 2022 we obtained the AAA Platinum Creditwothiness Certificate of Excellence.