Story 07

Revolutionary Receipts

Fully recyclable, free from thermal chemicals, and in a distinctive blue color: Koehler Innovation & Technology’s Blue4est® thermal paper has revolutionized the industry. Thanks to its sustainable properties, this innovative till roll paper has become well established in the retail sector. But the possibilities of Blue4est® do not end there by any means.

1 The Starting Point

Anyone wanting to develop genuine innovations has to truly know their stuff – and be able to recognize the signs of the times. The experts at Koehler Innovation & Technology proved they had this very instinct in abundance when they first started considering a new thermal paper in 2009. Thermal paper is commonly used in everyday situations, for example as till receipts, parcel labels, tickets, and in logistics centers. Koehler came up with a plan: To develop an environmentally friendly alternative that did not use any chemical color developers at all and was fully recyclable – and it did so even before the market was actively demanding such a product. “Today, sustainability is an extremely important megatrend. Few were interested in it back then. We anticipated this trend, and the regulatory framework that fortunately changed in our favor also played a part,” recalls Sebastian Früh, Director of the Thermal Paper Division at Koehler Paper.

2 The Development

Working in collaboration with suppliers, Koehler Innovation & Technology initially identified the key raw materials that enabled a new type of thermal paper to be developed for till rolls.
“We also needed a completely new effect mechanism,” explains Dr. Christian Kind, Head of Functional Surfaces and Microencapsulation at Koehler Innovation & Technology. “Instead of a chemical reaction, our innovative Blue4est® thermal paper uses a purely physical mechanism for its printing results.” He added that this means it is also approved for direct contact with food. Tiny air-filled pores in the functional layer collapse when subjected to heat from the thermal printhead, which results in the black layer underneath becoming visible. This means the paper does not use any chemical color developers at all. Koehler has patented this technology.

We don’t offer our customers any old paper; we help them to become more sustainable with our environmentally friendly technology. That makes me proud.

We don’t offer our customers any old paper; we help them to become more sustainable with our environmentally friendly technology. That makes me proud.

Sebastian Früh

Director of the Thermal Paper

Division at Koehler Paper

3 The Market Launch

Koehler held its first talks with customers in 2015. They were initially skeptical about the new type of till receipt. The change from white to blue and the altered contrast that this entailed provoked concerns about readability. In addition, interest in sustainable, recyclable products was not nearly as widespread as it is today. “Nevertheless, we managed to convince some customers to test Blue4est® – with success. The official market launch finally took place in 2017,” relates Sebastian Früh. Another milestone was reached when Blue4est® was given full certification from the Federal Institute for Risk Assessment. That signifies it is free from thermal chemicals, can safely come into contact with food, and can be fully disposed of as wastepaper, meaning it can be recycled. Another advantage is that the thermal paper is compatible with all commonly used receipt printers, so customers can still use their existing infrastructure. Acceptance of Blue4est® grew even further when customers realized that the paper does not lose its readability when stored for long periods or exposed to sunlight. Blue4est® is now used in many different supermarkets, gas stations, and other businesses. The blue color has become its trademark.

100 %

hydropower from regional sources: The raw paper used in Blue4est®, the new generation of environmentally-friendly thermal paper, has been manufactured entirely with renewable energy since 2021. That further highlights how sustainability has been a driving force behind the blue paper.

„I love it when I go shopping and get a blue receipt at the till. You can’t tell conventional thermal papers apart by looking at them, but our Blue4est® paper is immediately recognizable as being environmentally friendly.“

Dr. Christian Kind

Head of Functional Surfaces and Microencapsulation
at Koehler Innovation & Technology

4 The future

Is that the end of the story? Definitely not. Koehler Paper has expanded its blue product range and brought out Blue4est® Pro label paper in 2022. It is used in the highly promising market for self-adhesive labels – initially for fruit and vegetable scales at supermarkets. Other areas of use, for example in the logistics industry, are to follow. Blue4est® Pro is the world’s first thermal adhesive material that does not use chemical developers. It offers the known benefits, but also has an additional layer that protects the label against environmental influences, particularly mechanical damage. The color of the material is not an issue here either. But it has a striking effect – blue is the new green and indicates the paper is 100 percent sustainable and can be disposed of easily as wastepaper.

Story 04


Koehler Renewable Energy is building two wind turbines in the Blasbach district of Wetzlar.

Story 08

Sustainable Unpacking

The luxury watches from Mühle-Glashütte beguile in chic recycled packaging from Koehler.