Lot No. 365
| Auction No. | 30 |
| Category |
World Collections, Accumulations and Selections |
| Est. | $60 |
| Status | SOLD $120 |
Great Britain 1953-1967 study on leaves in binder of the process involved in the transition to phosphor usage on defins & commems. Incls 1971 cover with special slogan postmark used for one day only, "10 Years of Auto Letter-Facing" commemorating the first official use of the machine. Stamps start with the Naphthaday graphitelin experiment incl a strip of ½d on cover, the change of wmk & phos/graphite plus later phosphors mostly MUH. Page illustrating the various errors in positioning of graphite lines on 1d, first phosphor booklet panes, identified "green" & "blue" phosphors, changes of band width & errors on commems (e.g. offset of phosphor on reverse). Useful reference!