[Coco] yellowing of newsprint issues

[George Ramsower]

James,

  The old magazine ads I reproduce as posters on TheTinBox.com sometimes are not only yellowed, but so darned brown that I can't get a good photograph of them. So I soak them in a bleach mixture to get the paper back to as close to white as it probably was sixty to seventy years ago. One cup bleach to one quart water. Soak for about twenty minutes. Dry on a clean flat surface until it just begins to curl, then press between printer paper with good flat, untreated wood planks on either side.
  I usually experiment on a page I won't be using from the same magazine to be sure it won't bleach the ink. This hasn't happened yet, but I test anyway.
 I have not tried this on multiple color images. Only two color pages.

 Month before last, I had one that even the bleach wouldn't fix. So I scanned it into my photo software, did a color separation and kept the red one. That one is always the best,  followed by the green channel and the worst is the blue channel.

 As Robert Gault wrote, oxidation, not light is the culprit. Actually, the sun can do a little bleaching of the paper, but could also bleach the colors, other than black.

George



  ----- Original Message ----- 
  From: James C. Hrubik, Sr. 
  To: CoCoList for Color Computer Enthusiasts 
  Sent: Thursday, June 09, 2005 11:11 AM
  Subject: [Coco] yellowing of newsprint issues


  Working on a scan @ 300 / .pdf of the final issue.  Unfortunately, my 
  copy is somewhat yellowed - and it has not been exposed to much 
  sunlight.  Even the inside pages have yellowed a bit.  The glossy 
  issues don't seem to have this problem, or not that I'm seeing so far.

  +||||||||||###########################|||||||||||+
  +|||||||||  HRUBIK APPRAISAL SERVICES  ||||||||||+
  +||||||||   James C. Hrubik, Sr., RAA   |||||||||+
  +|||||||  Appraisal & Appraisal Review   ||||||||+
  +||||||  Consulting & Litigation Support  |||||||+
  +|||||||        V/F-(330)745-8435        ||||||||+
  +||||||||    jimhrubik at earthlink.net    |||||||||+
  +|||||||||#############################||||||||||+


  -- 
  Coco mailing list
  Coco at maltedmedia.com
  http://five.pairlist.net/mailman/listinfo/coco