Assembly of the composition

composition (assemblage des négatifs sur un support opaque)

composition (assemblage des négatifs sur un support opaque)

  • It’s about an operation there, which, without being difficult also has its importance for the obtaining of a good result. The purpose to be reached is the realization of the assembly which is going to support one or several photographic negatives. It is intended to be placed on the plate of photosensitive gelatin. During the sunstroke, the light U.V. will cross the photographic negatives to mark the imprint of the image on the dichromated gelatin. The parts that must remain white will be spared by the U.V. light.
  • A black cartoline is used to insure a waterproofness completed in the U.V. light, then cut with a razor blade or a cuter the locations there where will be inserted negatives.
  • Recut if necessary negatives so as to preserve a margin around the final picture of some millimeters only, for the covering with the adhesive tape.
  • Fix movies with the adhesive tape red inactinique. Watch not to create too much of on thickness with adhesive.
  • Negatives are positioned so, rather :
    • Digital negatives : place the side printed in direct contact with the coat of photosensitive gelatin. If problems of adhesion are met, to put talc very slightly on the plate of photosensitive gelatin or to insert a fine sheet of polyethylene ( mylar ). They are owed to the residual humidity which escapes from substrata and favor the adhesion of the ink of the movie about the gelatin of the plate.
    • Argentic negatives : place the emulsion in direct contact with the coat of photosensitive gelatin.
    • Avoid the reversal of negatives (that is avoid placing the emulsion or the side printed contrary to the photosensitive gelatin), especially if your light source is established by close UV tubes. This precaution allows to obtain a better delicacy of the image, by avoiding a light diffraction of the light.
  • The editor has any freedom, if he respects the usual rules of the masking for the parts which have to be on no account insolées. On the gelatin plate, contrary to the offset, it is not possible to erase an suntanned zone.