Muster-Schmidt has been cooperating with the RAL (German Institut for Qualtity Assurance and Labelling) in the development of binding colour samples since 1926.

The colour samples, which are tested according to the newest findings of coloremetry, are used as standards, and for many years, they have widely been accecpted in the countries of Europe, too. The current turnover of those colour cards is about 2 million copies.