The labor world. [volume] (Duluth, Minn.) 1896-current, 1905-05-27
POSTAGE STAMPS,
THEIR MANUFACTURE

L ue uISl MeCudulCd pTOCeSS III tuo
manufacture of postage stamps is the
cutting, or engraving Of the die. This
is piece Of steel Of the finest quality,
on the polished surface Of which man
slowly and patiently cuts, line by line,
the portrait or other emblem which has
been adopted for this particular stamp.
A steel engraving is what is called an
inctsed plate: that is, every line which
is to show in the finished point is cut
into the surface instead Of being left in
relief, as In wood engraving. says a
writer in the Youths Companion.
The die which the engraver cuts is
NEGATIVES" in other words. a reversal of
the design which the stamp will show.
The reason for this soon becomes appar-
ent.
When the die is finished and the proof
shows it to be satisfactory. It 10 hard
ened and fixed in the bed of a powerful
press Over it then passed steel roller.
the circumference Of which Is several
times-perhaps four times-the diameter
Of the die. Immense pressure is applied,
so that every line on the surface of the
die IS impressed upon the surface of the
roller as many times as the circumstance
Of the roller Is larger than the area Of
the die. In this way four perfect copies
Of the die are reproduced on the roller
but reversed. Each Of these impressions
Is "positive."
This roller is now hardened in turn in
order that 1t may transmit the impress
sions once more, this time to the plate
from which the actual printing is to be
made. This plate is also Of steel. The
size Is sufficient to print a whole sheet Of
stamps-from 200 to 300-at a single i'm
preston.
Into the surface Of this plate the i'm
preston on the roller is forced by great
pressure, once for each stamp In the sub
sequent sheet, and then the plate is
hardened. These impressions are neg
atives, so that the prints from them
the stamps themselves-wiu be positives.
The reason for all this preliminary work
is most interesting. In the first place
printing could not be done from single
die, because Of the vast quantities of
stamps required. In the second place
it could not be done from the roller. be-
cause on that the lines are in relief in
stead Of being incised; and in the third
place, it would not be feasible to have
several dies, or large number Of them,
ENGRAVED, both because the expense
would be proh.bitive and because no two
Of them would be absolutely alike. The
present system makes 1t certain that
every stamp Of a; certain lot is exactly
like every other Of the same lot-a great
safeguard against counterfeiting.
When three printing plates have been
made they are all fastened to the bed
Of special printing press. When the
machinery Is started the first plate is
linked, and then automatically wiped un-
til it is like mirror. The wiping re-
moves all the ink except what clings IN
the lines Of the 200 duplicate engraviugs
which dot the surface.
Over the plate is laid a sheet Of damp
ened paper, the plate Is slightly warmed
IN order to permit the ink to swell, and
heavy pressure Is applied. Meanwhile
the second plate is receiving the ink, and
then the third comes into play so that
although all three are on the same press.
each Is at given moment undergoing
different process from either Of the other
two This has wrought great saving
Of time over the old process Of printing
by hand. When the printed sheets are
dry they go to the cumming machine,
in which they pass between dry roller
on one side and one moistened with mu-
cilage on the other. From these rollers
they are cast out, wet side up, upon an
endless web, which carries them through
a steam heated box.
They come out dry ready for the per-
forations which permit them to be torn
apart easily. These are very easily made
by passing the sheets between one CYL
inder studded with steel pins and an
other perforated with holes to match the
pins. The two together act like the jaws
Of conductors punch.
The last process Is pressing the sheets
by hydraulic power to counteract the ten
dency to curl, which Is impaired by the
mucilage.
The printing Of stamps, like the print
ing of gold and silver certificates and
bank notes is subject to most careful
and constant inspection.
Every sheet of paper is counted before
1t Is delivered to the printer, and before
he goes home at night he must return
exactly the same number Of sheets, either
Of perfect stamps or spoiled paper, and no
seconds" or samples are given away to
visitors.
TEMPERATURE OF THE GROUND.