Journal of Film Preservation - FIAF

. Transplantation of image layer
1. Pour the image layer separation solution into a vessel 8-10cm
deep, maintaining the solution temperature at 15-18°. A high
temperature is apt to cause the dissolution of the emulsion layer,
while a low temperature is unfavourable for the separation of image
layer from the support.
2. Cut off c.1-2mm from the edges of the negative of which the
image layer shall be transplanted, in order to prevent the possibility
of adhesion between the support and its upper and lower gelatin
layers.
3. Place the negative, whose emulsion layer has wrinkled, into the
separation solution, constantly observing the changes of image layer.
Whenever the edges of image layer are found wrinkling, twist gently
with the fingers so as to separate image layer from subbed layer.
When there appears a greater part of image layer separated, hold this
with thumb and forefinger and carefully remove from subbed layer as
quickly as possible, taking care not to remove from the separation
solution. Leave the unfolded protective layer floating face-upward in
the solution.
4. Then remove image layer from the separation solution with a
bottom-upward accepting support, place onto the working table,
spread out smoothly with a Chinese writing brush, ease out airbubbles
and moisture, and then dry the newly-formed film in the air.
The whole transplantation work is now completed.
c. Note
1. Separation should begin from all sides, i.e., firstly separate 1-2cm
from each edge, followed by the whole image layer.
2. Wherever a crack appears on the layer, the separation direction
must be shifted immediately. Dividing the image layer into pieces
must be avoided at all costs.
3. If the subbed layer is separated along with the image layer, it must
be cleared away from the latter. The method is as follows: place the
image layer face downwards, remove from the separation solution
with film-base whiteout gelatin layer, then put onto the working
table; suppress the image layer with a writing brush (not with the
finger or other hard materials), and give the subbed layer a firm but
gentle push with the tip of another writing brush, so that it can be
gradually cleared away. Since such a process takes time, clean water
can be poured onto all sides of the image layer to prevent it sticking
to the support. When the entire subbed layer has been cleared away,
replace the image layer into the separation solution, then remove it
with a subbed film-base, smooth it out, brush out any air-bubbles
and moisture.
4. Before beginning such restoration work we must carefully inspect
the negative to be restored. This process cannot restore any negative
of which the emulsion layer is soluble in water. The cellulose nitrate
negative which has been restored by the image layer transplantation
37 Journal of Film Preservation / 58/59 / 1999
Restauration des ondulations du substrat
adhésif
La conservation de matériel photographique
dans un milieu à haute humidité relative
peut provoquer des dégradations telles que le
gonflement de la couche d’émulsion,
rétrécissement du support, séparation des
particules de plastique qui vont se loger de
manière irrégulière entre l’émulsion et le
support. L’ensemble de ce processus peut
provoquer des ondulations de la couche
d’émulsion. Les négatifs ayant subi ces
altérations ne sont généralement plus aptes
à servir au tirage de copies. Les auteurs de
l’article présentent une méthode qui permet
de restituer la forme originale des négatifs
photographiques par la suppression des
ondulations. Si cette méthode s’avère être
efficace pour les négatifs conservés dans des
boîtes qui permettent la circulation d’air, elle
ne l’est pas pour les négatifs conservés dans
des boîtes hermétiques.
(1) The Photographic negative of Premier
Zhou Enlai paying a visit to Moskow
(2) Photograph printed with the
transplantational restored negative of
photograph 1