The Mercator knife was trademarked by Heinrich Kaufmann & Sohne, Indiawerk, Solingen, Germany in 1867. Single blade and multi blade models were manufactured. The 'Mercator' trademark originates from the Latin word for the manufacturer's name 'Kaufmann', which translates into English as 'Merchant'.
The original, single blade knife was marked on the handle with the 'Leaping Cat' and 'K55K' logo with the second letter 'K' reversed. This trademark is derived from the initial of the manufacturer's name 'K', the street number of the factory address, '55' and the first letter of the German word for cat 'Katze'. The Heinrich Kaufmann & Sohne factory closed down in 1995.
Otter Knives have been manufactured since around 1840, with the trademark registered in 1867. The Solingen company has changed ownership and manufacturing location several times over the years. Established in 2010, Otter-Messer GMBH now manufactures Mercator brand knives.