20 Kwacha Blind mark at center right

This series has a mark on the obverse right hand side center, for visually impaired people. The 2012 notes did not have this.

There are several differences between the notes in this series:

2014, 2015, 2016 and 2017: there is a gold iridescent ink strip on the obverse with “RBM” visible. This strip starts to the left of the fish

2014, 2015, 2016 and 2017: the background pattern on the note has straight herring-bone pattern, no circles

2014, 2015, 2016 and 2017: the note has diagonal cornerstone watermarks on each corner

2014, 2015, 2016 and 2017: the watermark portrait of Inkosi ya Makhosi M’mbelwa II is the earlier version with the mouth closed

2019 and 2020: the gold iridescent strip is moved to the right so it covers the fish and now it also has the number 20 repeated four times below

2019 and 2020: there are no diagonal cornerstone watermarks on the corners of the note

2019 and 2020: the note now has concentric circular patterns 

2019: the watermark portrait of Inkosi ya Makhosi M’mbelwa II is the earlier version with the mouth closed

2020: the watermark portrait of Inkosi ya Makhosi M’mbelwa II is the later version with the mouth slightly open

See the image below:

© Brandon Bertolli

UV activity at 365nm:
 

At 254nm the obverse colouring can appear yellow instead of green:

There is also something very unusual about the 2017 version of this note. It is the only one in this series that has Anti-Stokes fluorescence on the note. The Anti-Stokes response comes from the same area on the obverse where the vertical rectangle is, readily seen under UV.  This feature was found on 15 different notes, all dated 2017.

This feature is difficult to photograph because it requires specialised equipment that can illuminate the note with infrared at 980nm and then photograph the visible light fluorescence.

The image below was acquired at the Foster and Freeman forensic company, using their VSC9000 device:

© Brandon Bertolli