Magazine Image Assembly

• Magazine Image Assembly
  • Elements of a publication must be assembled to create pages and signatures
    • Signatures are large sheets of paper on which 16 A4 pages are printed
  • or more of smaller size.
  • Press layout or imposition
  • Signatures are printed, folded, trimmed & bound
  • Plan needed so pages appear in proper sequence
    • Varies among printers depending on equipment

     

Offset Printing

• Composite negatives (flats) printed on photosensitive metal plates (positives)
• One for each colour
  
• Negatives stripped together and checked for holes
  
• Then plates are madefor each colour run
  • Plates for each colour imposition
    on the colour’s own press.
    
• A blueline print is used to check image position.
  
• Signatures are checked for quality control.
  • Clients may participate in this step.
    
• For both sheet-fed and web-fed presses
  • Only one colour printed at a time.
    • Additional runs for varnish; metallic inks
    • With each run, cost increases
• Signature is folded.
  • Folded signatures are stacked.
  • Center margin varied for shingling, or creep.
    
• The stitcher assembles and staples themagazines before trimming.
  
  

Impositions for sheet-fed printing

• Sheetwise
  • different pages on each side
  • 16 different pages (8 up)
    • Example: 1, 16, 8, 9, 13, 4, 5, 12 on side 1
        and   10, 7, 2, 15, 11, 6, 3, 14 on side 2.
      
      
• Work-and-turn
  • Front duplicates back (8 up)
  • Turned left to right, so same gripper edge
  • Cut in half before folding
    
    
• Work-and-tumble
  • Front duplicates back (8 up)
  • Turned up & over, so same side guide
  • Cut in half before folding
    
    
• Our magazine project
  • 16-page magazine with self-cover
  • Eight pages: four-colour process
  • Four pages: one colour
  • Four pages: two colours
  • Impositions (8 up):
  • Four-colours, printed work & turn (No. 1)
  • One and two colours, printed work & turn (No. 2)
    
    
• Plan your impositions
  • Take three sheets of typing paper
  • Draw lines for colour processes on two
  • Fold, stack & number the pages
  • Transcribe to diagram on third sheet for Signature & Imposition Chart
    
    
    

• Cut, fold and stack
• Number pages on lower outside corners.
  • Covers are 1 and 16.
• Unfold and transcribe to signature & imposition chart

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