Great Britain has never knowingly issued stamps with a Yellow phosphor reaction although some Machin issues had a Yellow phosphor reaction due to ink contamination. The Dollis Hill archive contained a few stamps and a few covers where Yellow phosphor had been used. Forster stated in his notes No watermark paper sized with Yellow emitting phosphor good emission but condemned as possibly toxic. The stamps are of Light Reddish Brown appearance and are usually a blotchy print. The distribution of the Yellow phosphor is patchy. Block of 12 with Gum. Ex Edward Klempka Author of the DOLLIS HILL FIND Cat 6000 pounds
Bloxham CategoriesPenny Blacks
1840 2d BLUE
Mulready's
Rainbow Trials and DPs
1841 Penny Reds
1841 2d BLUE
Penny Stars
2d stars
1/2d Bantam Plates
1d Red Plate Numbers SG 43
1 1/2d Plates SG51
SG45 2d Plates
Embossed Issues SG 54-61
Dollis Hill Wilding Trials
Commems
GB Overprinted
Surface Printed
Other QV
KEVII
KGV
KEVIII
KGVI
QEII
Wildings
Wilding Coils
Machins
Decimal Booklets
Smilers Sheets
Guernsey & Alderney
Jersey
Isle of Man
M/Sheets
Northern Ireland
Scotland
Wales
Officials
Postal History
Telegraph & Fiscals
Circular delivery
Postage Dues
Misc Products
Foreign
Prestige Books
Regionals England
Signed Artwork
1840 2d BLUE
Mulready's
Rainbow Trials and DPs
1841 Penny Reds
1841 2d BLUE
Penny Stars
2d stars
1/2d Bantam Plates
1d Red Plate Numbers SG 43
1 1/2d Plates SG51
SG45 2d Plates
Embossed Issues SG 54-61
Dollis Hill Wilding Trials
Commems
GB Overprinted
Surface Printed
Other QV
KEVII
KGV
KEVIII
KGVI
QEII
Wildings
Wilding Coils
Machins
Decimal Booklets
Smilers Sheets
Guernsey & Alderney
Jersey
Isle of Man
M/Sheets
Northern Ireland
Scotland
Wales
Officials
Postal History
Telegraph & Fiscals
Circular delivery
Postage Dues
Misc Products
Foreign
Prestige Books
Regionals England
Signed Artwork