The first publication with the 4+ trademark was published as early as 1991 (it dealt with the MiG-21 Fishbed). At that time it was the first aircraft monograph published in what was then Czechoslovakia which could be compared to similar publications issued by renowned foreign publishers.
Initially 4+ editorial plans concerned aircraft types in service with the Czechoslovak Air Force (later the Czech Air Force) which had not been fully described and only scarce authentic information was available on them at that time.
Since the 1990s the coverage has been further extended and also includes British-produced aeroplanes.
The authors’ goal is to describe a particular aeroplane or helicopter from the technical point of view rather then depict its operational use and function. This is the reason why the core of 4+ publications is quality photographs taken by the authors themselves or by the contributors, and period pictures from various aviation archives worldwide.
Included in the publications are original scale plans made using the maker’s drawings and documentation, photographs and – when available – measurements of real machines, and accompanied by drawings of important components like instrument panels, construction assemblies etc.
A short text covers the history and summary of the particular aircraft, its variants, a technical description, camouflage and markings, and an armament and equipment description. An important part of the publications are the photo captions which go into further detailed information.
The 4+ publications are aimed at aviation enthusiasts, historians and also scale model builders and plastic modellers.
In 2005 a second, newly-conceived line of monographs, called “MARK I guides“, first appeared. These publications are intended primarily to serve plastic modellers who are thus supplied with a wealth of valuable photographs and detailed information about the type, including alternative camouflage schemes to help them finish their scale models.