2nd class blue Machin security stamp counter sheet 2018 version M18L
The 2nd class counter sheet was reprinted on 14/02/18 by ISP Walsall, and was distributed by Royal Mail Tallents House on 23/05/18. The phosphor reaction is bright blue.
The first reprint didn't occur until 29/10/18, and was available from Royal Mail in December. This printing has dull blue phosphor with no hint of yellow.
SG U2995 - previously U2957 (also used for earlier years).
Cylinder blocks of 6
Date block of 8 - 29/10/18