Technical Specification:
The obverse depicts a portrait of the writer Pencho Slaveykov, fragments of the buildings of the National Theater "Ivan Vazov" and the National Library "St. St. Cyril and Methodius ”; vertical texts "Pencho Slaveykov" and "1866-1912"; the face value of the banknote in figures and words.
On the reverse side are depicted texts from the works of Pencho Slaveykov, an illustration of a bird from his poetry collection, a figure of the poet Mara Belcheva, and the denomination of the banknote is marked with numbers and words.
Predominant color - brown.
Material - paper, tinted in pale red color, with lacquer coating after printing.
Size - 136 x 76 mm.
New security features
Additional sign for blind citizens - consists of four thick and seven thin lines located at an angle to the two short sides of the banknote.
Holographic tape with optical effects - alternating when changing the angle of observation images of a bird and Icarus; color holographic portrait of Pencho Slaveykov; a book that changes color from golden to green when the viewing angle changes; dynamic "flame" effect with a change in color from golden to green when changing the viewing angle and a three-dimensional image of the number 50.
Optical Ink - The number 50 is printed with a color-changing ink with a dynamic "flame" effect, which changes from golden to green when the viewing angle changes.
Security thread - embedded in the paper and partially protruding from the reverse side with bright repeating text "BNB 50" and with a dynamic effect "flame", changing color from golden to green. The image of the repeating text "BNB 50" is read on the obverse when placing the banknote against a light source.
High-resolution watermark - observed when placing the banknote against a light source. It consists of a high-resolution halftone image of the portrait of Pancho Slaveykov. The images are also visible on the back of the banknote.
