Hi there, I've been reading with much interest several posts regarding those transparent type rainbow holograms that seem to be everywhere nowadays. I was just wondering, as these seem to uniformly reflect the light so that the colour is constant across the image, would it be possible then to use a clear foil with this property and then just to heat stamp or cut your image out of it ?
Sorry if this is a silly question but just a thought.
General question - easy way to access hologram security ?
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Hans
General question - easy way to access hologram security ?
That is how the industry does it. The rainbow hologram is actually a transparent transmission hologram that has been exposed in such a way that it can be viewed when white light is shone through them (not reflected off them). If you place a mirror behind that type of hologram, that mirror will re-direct light that comes from the front and reflect it back through the medium, allowing the hologram to do it's work.
The type of holograms that most hobbyists make are recorded in subtle variations of density in gelatin (either caused by differing concentrations of AgBr remaining in the gelatin or by air pockets made in a DCG process).
But it is equally possible to make holograms that are made by creating a step-wise grating on the surface of a light sensitive medium. This can be done with fotoresist, DCG, SHSG and some Photopoylmers. This surface grating can be copied onto a thin sheet of very hard metal. This metal can then be used as a stamp to copy the hologram onto plastic sheets. These plastic sheets have a mirror coating on the back so they can be viewable when glued onto non-transparent objects such as phone batteries and credit cards.
The type of holograms that most hobbyists make are recorded in subtle variations of density in gelatin (either caused by differing concentrations of AgBr remaining in the gelatin or by air pockets made in a DCG process).
But it is equally possible to make holograms that are made by creating a step-wise grating on the surface of a light sensitive medium. This can be done with fotoresist, DCG, SHSG and some Photopoylmers. This surface grating can be copied onto a thin sheet of very hard metal. This metal can then be used as a stamp to copy the hologram onto plastic sheets. These plastic sheets have a mirror coating on the back so they can be viewable when glued onto non-transparent objects such as phone batteries and credit cards.