Modern textiles rely heavily on petrochemical products that come from many of the same oil and gas companies driving greenhouse gas emissions. Today, in fact, fashion accounts for up to 10% of global carbon dioxide output—more than international flights and shipping combined, according to the United Nations Environment Programme. 48 million tones of clothing are disposed worldwide every year. 73% are incinerated, 12% is reused, 12% is downcycled, and only less then 1% is turned into new clothes.

Generally, Klee Klee's clothing is very much in line with the current trend of "slow fashion", manufacturing high-quality and long-lasting clothing. In terms of design, Klee Klee removed the obvious logo and paid more attention to the daily wear of the clothing. This choice is part of the company effort to slow fashion by promoting emotional durability through simple designs that are not influenced by fashion trends. In the same direction, each product comes with a history of its production process to foster emotional attachment. At the same time the company pursues physical durability by offering repair of its products for free.

Since its establishment the company has insisted on using environmentally friendly materials to make clothes. It uses organic materials and avoids the use of chemicals in processing. Klee Klee experiments with natural dyes such a natural color, plant dyeing, denim ozone washing and Indigo Juice. Klee Klee environmentally friendly dyeing processes can effectively reduce water consumption by 50%. Clothing buttons are made from reycled PET bottles.