GMG was founded by Ewald Weihing on 1 April 1984, and is today owned by the second generation of the family.

In the early years, the company's business activities focused on the sale of machinery for the graphic arts industry. It was in the 1990s that the first color control system was developed for the IRIS proofer. The great success of this solution was attributable to the excellent color quality and repeatability of the proofs, which have remained the hallmark of GMG to this day. As a result of this success, GMG became the de facto proofing standard in Europe's demanding gravure printing industry.

The growing market penetration of significantly cheaper inkjet printers, particularly from Epson, led to the GMG solution also being increasingly used in classical offset printing. Several branches have been established since 2003, and representatives now handle the interests of GMG around the world. Today, GMG has its own subsidiaries in the UK, the USA and Japan, and is represented by authorized dealers in all important countries worldwide.

GMG is a leading developer and supplier of high-end color management software solutions. More than 11,000 systems are in use at customers around the globe. These customers are to be found in numerous branches of industry and fields of application, including advertising agencies, prepress houses, offset, flexo, packaging, digital, and large-format printers, as well as international gravure printers.