Radiotone process on copper plates

Discussion in 'Alternative Processes' started by filmtopixels, Oct 30, 2007.

  1. filmtopixels

    filmtopixels Member

    Messages:
    1
    Joined:
    Aug 28, 2006
    Location:
    SE PA
    Shooter:
    35mm
    We've been trying to figure out what a "Radiotone" print is over here.

    The "print" in question is made on a copper plate about 1/16" thick. Appears to be at least from the turn of the last century. I figured that maybe someone from this forum may be familiar with the process. Nothing comes up on a Google search.
     
  2. htmlguru4242

    htmlguru4242 Member

    Messages:
    973
    Joined:
    Aug 9, 2005
    Location:
    Sandy Hook,
    Shooter:
    Multi Format
    That's a neat looking picture. No idea what it is, though I'm sure that someone here will know.
     
  3. PHOTOTONE

    PHOTOTONE Member

    Messages:
    2,411
    Joined:
    Oct 30, 2006
    Location:
    Van Buren, A
    Shooter:
    Large Format
    The use of the word "Radio" in a product name "may" be just capitalizing on the popularity of Radio. I have seen this many times in products from the 1920's, and 1930's, when radio was going great and everyone wanted to be associated with it.

    The images posted of this photo appear to be from the 1920's. Making an image on copper plate is not that unusual, although primarily engraving on copper plate was done for making printing plates. It would be only a minor modification of the copper plate engraving process to produce a positive image for viewing. The plate-making process involves exposing a plate with a UV-light sensitive coating, with a negative. The coating is "developed" leaving behind a layer representative of the image, and then the plate is acid-etched to create peaks and valleys in the metal which represent the image. If the valleys were filled with a pigment, then you would have an image such as the one shown in the sample linked thru the discussion linked in the first post.

    The image-making process is not very unique. The "name" of the Process, "Radiotone" is probably a trademark of one vendor for this process, rather than a generic name for the process.
     
  4. htmlguru4242

    htmlguru4242 Member

    Messages:
    973
    Joined:
    Aug 9, 2005
    Location:
    Sandy Hook,
    Shooter:
    Multi Format
    I looked around online a bit, and found this:
    http://www.sharlot.org/archives/photographs/19th/book/chapter_9.html

    It could be a transfer of a silver-gelatin emulsion onto the copper.

    Also, this is interesting.
    http://www.icom-cc.org/Documents/Wo...rimMeeting/2004/ClaravonWaldthausenPoster.pdf

    The PDF makes a brief mention of "the Radiotone photograph". It states that it looked like a half-tone photograph, but XRF (X-Ray Fluoresence) analysis proved otherwise. No more detail is given, but from this I'd assume that its less likely to be a litho print or pigmented etch process.