Douglas Myall in DGR118 has offered new classification for dull phosphors that are appearing on several values : 1p 2p 5p 10p 20p 1£ 1st and 2nd values
Q. printers are varying, the sequencing cylinder?
I have tried to rationalize dull and bright phosphors
(as PUI , phosphor under ink)
IUP , Iriodin® under phosphor
my survey of values has revealed a spectrum of flour-phosphors :
very brite / brite A2B / dull A3B / very dull / none MFP