Colour Trials
1881 trials (Young) [S] 22(1)4, (Young) [M] 28(3)74
1881, earliest inks for 1d lilac (Young) [L] 45(4)75, (Young) [L] 48(2)25
1883 trials (Young) [S] 22(1)5
1883-84 Lilac & Green, without corner letters (Ffooks) [L] 33(2)21, (Wiseman) [S] 33(3)52, (Ffooks) [M] 33(4)69
1884 2d (Phillips) [S] 29(3)46
1884 trials (Young) [S] 22(1)4, (Young) [L] 23(4)52, (Young) [L] 24(5)74
1888 coloured paper trials (Young) [L] 24(5)74
1892 4½d trials (Young) [S] 25(2)26
1899-1900 trials (Young) [M] 25(2)26
Chalk‑surfaced paper, 1905 (Powell) [S] 22(1)13, (Powell) [M] 25(2)38
Coloured Paper Scheme, 1884 (Young) [S] 22(1)7
De La Rue (Young) [L] 21(6)74
KEVII & KGV 2½d (illustration) (SWL90) [N] 28(2)36
KGV turquoise on yellow (illustration) (SWL90) [N] 28(2)36
KGV, 1913 2s 6d Seahorse (illustration) (SWL90) [N] 28(2)44
— 1913 3d colour essay, control block of 6 (illustration) (SWL90) [N] 28(2)44
— Huber inks (Wilkinson) [N] 33(4)73
— PUC £1 (illustration) (SWL90) [N] 28(2)44
Machin, Cambridge University, 1969 (Walker) [L] 48(3)63, (Walker) [L] 48(4)92, (Walker) [L] 48(5)123
Penny Lilac (Young) [S] 22(1)5
QV Line‑Engraved colours and the 'Penny Blue' (Gibbons‑Partridge) [M] 32(4)78
Rainbow Trials, wax not used (Hollins) [L] 43(4)73
Rainbow trials, (Durham Collection) [N] 31(5)92
— end of State 2, beginning of State 3 (Rowse) [M] 30(5)89
Thorpe, Dr Thomas Edward, chemist at Somerset House (Dagnall) [M] 34(5)91
Underprint advertisement, 1889 colour trial (Young) [S] 25(2)28