Regummed Stamps - How to tell a fake

Original Gum   (OG)

Note : I neither support nor reject this commentary, offered for the individual's own reflection / collection.

ORIGINAL GUM CAN BE DETRIMENTAL
SAYS ERNEST A. KEHR (in "Western Stamp Collector")

Original gum, or "OG" as it is popularly known, is the most costly item in philately today. And the
mad stampede for it is continuing to worry knowledgeable collectors.
At every counter or auction sale, dealers are getting two and more times for items that can be
described as having OG and being never previously hinged than they do for the same stamps that do
not have these questionable advantages.

OG demands are neither logical nor wise and were created by misinformed speculators of the past.
There are certain 19th century classics (such as Hanover's 1850 issue) that can be differentiated
from reprints only by the colour of their gum. And because philatelists want proof of genuineness,
they pay premiums to have it on the backs of such stamps.
This led many a neophyte to demand OG on all stamps, erroneously thinking that experts were
spending the extra money for the stickum generally, rather than to distinguish a relatively few
isolated issues.

Gum actually is detrimental to postage stamps. Some adhesives contain chemicals that can discolour
the paper and ink used in stamp manufacture. Moreover, gum usually shrinks much more and faster
than the paper to which it is applied. This eventually will cause a stamp to crack, destroying its
value.

It is incredible how many fine specimens have been permanently ruined by such paper cracking. The
danger to mint blocks is even greater, for perforations break rather rapidly.
Only last year at the IBRA international show in Munich, several early Japanese sheets that were the
only ones of their kind known to exist and rare panes of Palestinian and Gambian issues were
damaged by this gum shrinkage and perforation breakage during their display.
Through the years, experts frequently have sounded warnings, but it seems to have made little
impression on those who think of stamps more as "investment" merchandise than as philatelic
treasures to be preserved for the future.
Those who insist on OG reason that because stamps with it command higher prices now, it will be
the same in years to come. They simply don't realise the peril that threatens the very existence of the
stamps themselves.

Mixing Dextrine B Gum