At the conclusion of preparing a photo-resist master, the holographer is left with a laser etched, developed plate of glass that is normally coated with a fragile positive reading resist.
Encoded in its surface are the many fine grooves that produce the image. This coated glass cannot be used to emboss copies of the hologram into plastic. Therefore, the electroforming process is used to perform the conversion from photo-resist master to metal master for the subsequent production of copies in plastic or hot-stamping foil.
Electroforming, which has been utilized since the mid-19th Century, is basically an electroplating process in which the substrate plated onto is separated from the plated portion.
In other words, the metal master is grown upon the glass master and then separated from it. The resultant metal master is then used to grow further metal masters or "shims", which are used to emboss it into plastic or hot-stamping foil.
Due to the excellent reproduction of even the most minute detail,electroforming is perfect for use in the holographic field and, indeed, provides a crucial step in the embossing process.
The standard electroforming system is provided with two types of plating tanks (both using the same equipment - only different strengths of plating solution. |