Omaha daily bee., 1906-03-10


must not be warmer than 20 deg. c. ANY
bubbles of air should be removed with the
\ finger or a brush. A great number Of
plates may be sensitized one after another
| in the same bath. After the plates have
| been sensitized they are well drained and
dried in a dark and not too warm place.
/ free from dust.
The sensitized plates keep much longer
than sensitzed pigment paper and pre-
serve their qualities completely for two or
three weeks.
The diapositives to be copied are laid in
a frame with the film side in contact with
| the film side Of a sensitized print plate.
The frame is then closed with a good spring
and exposed, the exposure time for a print
plate being about the same as that for
colodin paper.
Electric arc light is just as good as d.
rect sunlight for copying.
After copying the pictures should be dis
/ tinctly seen in brown color on yellow
background. The print plate is now washed
/ in running water until all decomposed
chrome has been removed. Usually wash
/ ing is complete in ten minutes. The plates
may now be dried placed directly in the
/ dye solution.
The wellwashed print plate, either dry
or moist. which corresponds TO the red I'll
| ter negative, is stepped in the blue dye So
| luton composed FIVE grammes of pinatype
/ blue dissolved in $50 &C. of water and the
dish osclllated from time to time. The
first dyeing occupies about fifteen min
/ utes The plate is then washed and rinsed
until the water running OF from IL Is 10
longer colored. 1t should have the appear
ance of a dapositive full OF detail, with al
most transparent whites and intense
shades.
Clearing the Bubbles.
II the printed shade is successful a piece
of transfer" paper of the size Of the
! printed plate is now softened in cold
water, all the air bubbles being removed,
| until the paper has become completely
pliable and fully distended. The paper IS
now attached to the plate, preferably under
water, with film side against the film side
of the printed plate and both removed
from the bath, at the same time draining
off the excess of water by a gentle mo-
ton of the hand.
| The plate is then laid upon a table, paper
uppermost and protected with piece of
| oiled silk or the like. and the paper firmly
| smoothed over with a rubber squeegee
from the middle outward using moderate
! pressure. The operation is similar to that
| in the pigment process.
! When the paper adheres satisfactorily it
is covered with a damp sheet and a glass
| plate in order to prevent evaporation, and
| the whole allowed TO stand for ten to fif-
teen minutes, if desired, under a light
weight. After the lapse of the above
period the picture will be found transferred
to the paper with SUFFICIENT strength. The
paper is now removed and hung up to dry.
The print plate is now again placed for
/ about five minutes in q dive hath rinSad
and the picture again transferred to paper
as above directed. These operations may
be repeated as often as desired
BY repeated immersion in the dye bath
the print plate becomes darker. Neverthe-
less the prints from the plate are quite
uniform, as only the exterior surface Of
the dyed plate has action on the paper
The dye plates may be kept for anv
length of time after use, and can at any
time be again employed after a fresh inn
mersion in the dye bath.
The dyeing of the print plate correspond
ing with the green hitter negative is done
IN the same manner
For the dye bath five grains of pinatype
red are stirred with a little water to a
paste and then three to FIVE &C. concern
trated ammonia solution added. sufii-
cient ammonia must be used to completely
dissolve the dye 10 clear deep red liquid.
After about five minutes the solution is
diluted with cold water to $50 &C.
After the red plate has been washed free
from the excess of dye stuff the blue pic
ture is softened in water and laid under
water upon the red print plate. The o.
Grafton is carried out in the same way as
before described. the blue picture being
easily shifted under water so as to COM
pletely correspond to the red print plate.
When the adjustment is complete the
paper is held firmly against the plate with
suitable clamps. leaving the film free; the
film is then withdrawn water again run
over the plate and then the paper pressed
firmly down with the sqeegee. 1t lie al
lowed to stand for ten to fifteen minutes
and the paper then removed from the
plate.
Some Important Details,
About thirty minutes should be allowed
for the first immersion of the print plate
corresponding to the blue filter negative
in a dye bath composed of five grams OF
pinatype yellow dissolved in 200 CO. of hot
water; for subsequent dimensions Ave to
ten minutes. The yellow transfer upon
the blue and red picture occupies about
thirty minutes. 1t is advisable to well
moisten the superimposed damp sheet In
order to prevent the films adhering to each
other
To increase the pictures fastness to light
and to harden the gelatine layer the paper
, is now immersed from one to two min
utes in a fixing bath of two grams ixa
tive and 100 &C. water. After fixing tbs
picture is washed for about five minutes
in clean water and hung up to dry.
The principal advantages OF pinatype arr
the print plates, which are prepared in
. simple fashion with the aid of light; ALLOW
the preparation OF a large number of pape
copies therefrom by a purely mechanica
process, without further recource TO light
The print plates can be kept and at an!
time used without the aid OF light for IN
preparation of paper copies. In conse
quence of the intensity of the plnatyp
| dyestuffs and the immunity from spoiled
pictures pinatypes are very cheap. Pima
types are extremely fast TO light. tire
Y colored pinatype is not composed Of DIFF