methods of image planning & assembly_1

8/7/2019 Methods of Image Planning & Assembly_1

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METHODS OF IMAGE PLANNING

& ASSEMBLYHand assembly

Negative assembly to Gold rod with plastic interleave

Peelable membrane substrates

Conventional +ve assembly


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HAND ASSEMBLY

Hand assembly is also called as stripping

In olden days the films are obtained from the

camera department and these output films are

assembled according to the size of themachine/substrate in Planning department

There they do all the pre make-ready processes

involved in platemaking with respect to film.


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STRUCTURE OF AHAND ASSEMBLED FORM


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NEGATIVE FILM ASSEMBLYWITH GOLD

ROD

Golden rod is not a metal rod. It is a kind of

paper.

Golden rod paper is the most popular image

assembly material used for preparing negativeplates

It serves as a mask to protect the nonimage areas

of the press plate

The colour of the paper limits passage of actiniclight (light that exposes a coating or emulsion)

Widely used for single colour and book work

under negative processing. Not suitable for

precise register work.


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PROCESSING WITH GOLDEN ROD PAPER


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PROPERTIES OF GOLDEN ROD PAPER

True golden rod paper is yellow in colour

Many papers called golden rod are orange, serves

better to block actinic light

Red papers are also available and are best forblocking light

Golden rod paper will change size appreciably if

there is more than a 20% change in relative

humidity The thickness can vary from 0.004in0.005in

(~90 gsm)

It can be either single side coated or double side

coated material


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DISADVANTAGES WITH GOLDEN ROD

Due to change in relative humidity the size of the

material gets changed this is the major

disadvantage with Golden rod papers

This thickness variation can cause gap betweenthe film and the press plate during exposure in

the vacuum frame

If a problem develops with gaps around the edges

of the halftone before exposure in a vacuum

frame, contact can often be improved by laying a

sheet of 0.0005in cellophane over the plate before

drawing up vacuum


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PEELABLE MEMBRANE SUBSTRATES


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CONVENTIONAL +VE ASSEMBLY

This process uses reverse principle from negative

assembly with golden rod paper.

Here we use transparent sheets as a supporting

materials for the film Stripping a positive film over a transparent sheet


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WORKING OF +VE FILM


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PLATE EXPOSURE IN APRINTING DOWN

FRAME


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ADVANTAGES

These transparent sheets used for assembly can

be reused

Good stability due to the resistance of the

material These are plastic materials, wont expand much

due to change in relative humidity

methods of image planning & assembly_1

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