The currency reform in the three western occupation zones of Germany on June 20, 1948 formed the basis for West Germany’s impressive postwar recovery (Buchheim 1998, Pelikan Schreibgeräte). From then on, several German manufacturers started producing their school pens by modifying preexisting adult pens (Pelikan Schreibgeräte)⁽¹⁾. On May 23, 1955, Pelikan also entered the market of school fountain pens with the announcement as below:
 
"PELIKAN-SCHULFÜLLER - Der Pelikan 120 besitzt das typesche Merkmal der Pelikan-Füllhalter: die grüne Binde. Der tintenbehälter ist zum Teil durchsichtig. Eine fortlaufende Nummer beugt etwaigen späteren Verwechslungen in der Schule vor. Die vergoldete Stahlfeder des Pelikan 120 ist mit einer harten Spitze versehen. Schnell und sauber füllt die kräftlige Kolbenpumpe den großen Tintenbehälter (Pelikan catalog No.90 (1955))"
 
(PELIKAN SCHOOL FOUNTAIN PEN - Pelikan 120 has the typical feature of Pelikan fountain pens: the green sleeve⁽²⁾. The ink reservoir is partially transparent. A serial number prevents mix-ups at school. The gold-plated steel nib of Pelikan 120 has a hard tip⁽³⁾. The powerful piston pump fills the large ink reservoir quickly and cleanly)

Although the model 120 was a school pen modified from adult fountain pen (model 140) (Pelikan Schreibgeräte), model 120 had features that model 140 did not have. It was equipped with a gold-plated steel nib. Although only F and M nibs were available at introduction, later other types of nib became available (Pelikan catalog No.100A/4 (1962)). In particular, Pfannen (PF) nib⁽⁴⁾ was available only in model 120 (and Pelikano). Model 120 had a transparent non-striped ink window⁽⁵⁾. The serial number was engraved on the barrel⁽⁶⁾. Although it was a school pen, model 120 had the same specifications as model 140 except for the nib and barrel. The cap tube was reinforced with the metal tube, and late production had a cap safety device (for a limited time).
 
Like model 400 and 140, model 120 also had desk set. They were produced (or assembled) in Pelikan Milan factory.

In 1960, Pelikano (model 1) was introduced as another school pen⁽⁷⁾. Pelikano was the first cartridge pen from Pelikan. From then on, both model 120 and Pelikano were advertised as school pens (e.g. "PELIKANO Schulfüller mit verdeckter edelstahlfeder (PELIKANO school fountain pen with concealed stainless steel nib)" and "Schulefüller 120" (Pelikan catalog No.100A/4 (1962)), "Kolben (piston) -Schulfüller 120" and "Patronen (cartridge) -Schulfüller Pelikano" (Pelikan catalog No.110B (1963)).

In January 1965, new Pelikano (model 2) was introduced. On the other hand, model 120 was discontinued on May 23, 1965. Model 120 can be said to have fulfilled its role as the first Pelikan school pen.

​Note;⁽¹⁾Pelikan's competitors such as Soennecken and Geha started producing school pens in 1950's (e.g. Soennecken S4, Geha 700) 
⁽²⁾We can see that the green barrel was already acknowledged as an undisputed trademark of Pelikan fountain pens at that time. But interestingly, blue was chosen as the symbolic color of Pelikano.
⁽³⁾This would have referred to the osmi-iridium point. According to Pelikan catalog No.100A/4 (1962), "harter Spitze aus Edelmetall"(hard tip made of precious metal). 
⁽⁴⁾According to Pelikan catalog No.110B (1963), PF nib was "Pfannenfeder für Schulänfanger, wird nur für Schulfüller geliefert" (pan nib for school beginner, supplied only for school fountain pen). According to Pelikan Schreibgeräte, the nib was similar to the steel pan nib for dip pen (used for calligraphy characterized by wide and flat tip).
⁽⁵⁾Presumably, the style of barrel was chosen because of the simple design for a school pen and the visibility of remaining ink.
⁽⁶⁾In 1958, Pelikan launched an advertising campaign, in which students got a blue-gold pin badge by sending the serial number to Pelikan. However, there were model 120 without such a number like mine. With the introduction of Pelikano and other competitors, the need for the number probably diminished in the later stages of production.
⁽⁷⁾Although its design and engineering of the inner feed were based on model P1, Pelikano was the first school pen that was developed based on the extensive market survey including the thousands of educators evaluating school pens (Pelikan Schreibgeräte). Pelikano fitted the needs of children who were learning to write, and brought Pelikan so much success that production could not keep up.