Stripping film
When stripping film was originally referred to a paper film , the 1884 by George Eastman has been developed and the Eastman Company , the 1881 Eastman Dry Plate Company founded in 1889 and Eastman Company was renamed was made.
From the end of the 1960s, Agfa offered a stripping film, which consisted of a thicker carrier film made of polyester with a thin film on it with the photosensitive emulsion layer. This was used in particular in card production and continuation and in prepress .
functionality
The former was a gelatin- coated roll film in which the gelatin layer (the photographic emulsion ) was peeled off after exposure and transferred to a glass plate; the image on the glass slide then had to be transferred again onto a layer of gelatin in order to produce prints . Kodak No. 1 , for example, worked with this type of film .
Paper as a carrier did not prove to be particularly practical in further processing, so Eastman replaced the carrier material with the celluloid a little later ; the successor product was marketed under the name American Film , a celluloid film , from 1891 .
meaning
The often rumored assessment of the stripping film have the amateur photography triggered proves on closer inspection to be fotohistoriografischer legend; As the photo historian Timm Starl shows, for example , private image production by amateur photographers started much earlier. The claim that George Eastman invented roll film also turns out to be a legend launched by Kodak's marketing department.
From the 1890s onwards, roll film made competition for the photographic plate; Plate cameras lasted until the 1930s, but they steadily lost their market importance.
Use in prepress and cartography
When Strip film or Strippingfilm into which is also prepress mainly to correct text errors or addition of logos and emblems used line film called. On its emulsion side, the desired motif or text is exposed or contacted correctly and positively . After the development , a transparent, double-sided adhesive strip or a thin adhesive film is applied to the emulsion side and is thus adhered to the offset film to be corrected ; then the carrier material is peeled off so that only the emulsion remains adhered to the film to be changed. The advantage of this method compared to inserting normal reprofilm in the offset film assembly was the elimination of the carrier material and thus the reduction or avoidance of light scattering at the interfaces between the correction film / carrier film / offset printing plate during the subsequent exposure to the offset printing plate .
For use in card production or continuation, a stripping film (from Agfa ) was exposed over contact copies and negatives . The characters that were now on the thin film were scratched with a sharp scraper / scalpel / knife after application of a contact adhesive (e.g. wax) and detached from the carrier film, placed on the original card, if necessary (e.g. when marking curved bodies of water or winding roads) cut and bent and then rubbed / fixed.
The processes described were still in use until the 1990s, but were pushed back in the printing industry with the increasing spread of phototypesetting from the beginning of the 1970s through increasing full-page corrections. The ability to easily insert special characters and logos into printed matter in the DTP area almost completely ended the use of strip films. Stripping film has not been produced for several years.