Chemische Fabrik Dr. Gossler GmbH

Innovative indicator dyes for the textile and paper industry


The history of "FESAGO"

In 1930, "FESAGO" was founded by Felix Sager and the chemist Dr. Heinz Gossler in Heidelberg. With its tradition of more than ninety years, the company is today a recognized specialist in the field of indicator dyes. The product portfolio includes a wide range of reagents that are used mainly in the paper and textile industry.

“FESAGO” - a subsidiary of MATSEN CHEMIE AG

Since December 2017 "FESAGO" is a one hundred percent subsidiary of MATSEN CHEMIE AG, based in Hamburg. Since then, the entire "FESAGO" product range is exclusively available at MATSEN CHEMIE AG. Further information about the company and its whole product portfolio can be found here>.  

MATSEN CHEMIE AG | Weidestraße 122 a (2nd floor) | 22083 Hamburg | Germany
+49 (0)40 6505559-0 |

Our products

In compliance with strict quality standards, all "FESAGO" products are manufactured exclusively in Germany.

"FESAGO" Indicator-Spray

The reagent spray for the detection of silica sol on surfaces

The colourless "FESAGO" indicator spray makes colloidal silica visible on surfaces within seconds. After application, the indicator reacts immediately with any silica particles that may be present, expressed in a varying degree of reddish colour. The intensity of silica particles can now be determined by comparing the discoloured surface with the scales on the outside of the can - one can be used for white paper, the other one shows the typical discoloration on brown paper.

The "FESAGO" indicator spray is primarily used for quality assurance, when manufacturing paper bags. In the paper and packaging industry, colloidal silica (sinasol®) is applied on the surface of paper bags as an anti-slip agent to ensure the stability of bags, stacked on pallets.

Easy to use, reliable results and "made in Germany" - these are the success factors of the "FESAGO" indicator spray for several decades. The "FESAGO" indicator spray is available exclusively at MATSEN CHEMIE AG.



The quick identifier of textile fibers

Our Neocarmin products are special indicator solutions for the quick and clear determination of textile fibers. Whether cotton or synthetic fiber - up to 30 different types of textile fibers can be clearly identified within a few minutes using the color scale provided. All Neocarmin products are exclusively manufactured by "FESAGO" – quality "made in Germany".


Use and properties

Neocarmin is a ready-to-use dye solution for the quick and easy identification of synthetic and natural textile fibers. The fabric samples treated with Neocarmin change color within a few minutes depending on the type of filament. The respective fiber type can be clearly identified by using the corresponding color scale. Because of this quick and reliable proof, Neocarmin solutions are still the state of the art products for quality control, especially in the textile industry.

Neocarmin is available in five different versions:

  • Neocarmin B
  • Neocarmin MS
  • Neocarmin OB
  • Neocarmin TA
  • Neocarmin W

Characteristic for the entire Neocarmin portfolio is the low use of materials - reliable detection can be carried out with a fingernail-sized sample section. We would be happy to advise you which type is best suited for your application. All of our indicator solutions are exclusively available at MATSEN CHEMIE AG.


The simple identifier of oxycellulose

In addition to Neocarmin, Oxycarmin is an easy to use reagent for the clear detection of oxycellulose on natural fibers. Unlike other indicators, Oxycarmin only reacts with oxycellulose and not with hydrocellulose.

In case of Oxycarmin, the indication takes place in a two-stage process. The fabric samples are treated one after the other in the two different Oxycarmin solutions. The oxycellulose can then be recognized by a dark, blue-violet coloration, while the undamaged fiber remains white.


Contact us

Do you have questions or are you interested in our products?
We are glad to be here for you!


"FESAGO" – Chemische Fabrik Dr. Gossler GmbH
Weidestraße 122 a
D-22083 Hamburg

+49 (0) 40 | 650 555 990