Using the same 3D optical data storage technology as the fluorescent multilayer disc, the fluorescent multilayer card was a memory device proposed by Consallation3D. 3D optical data storage is the term given to any form of Optical Data storage in which information can be recorded and/or read with three dimensional Fluorescent Multilayer Disc ( FMD) was an Optical disc format developed by Constellation 3D that uses fluorescent, rather than reflective It consisted of a card containing a square shaped clear part with multiple layers each containing a different fluorescent material capable of emitting light at a different wavelength from the other layers. Fluorescence is a Luminescence that is mostly found as an Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 In Physics wavelength is the distance between repeating units of a propagating Wave of a given Frequency. By this approach, the device could contain several layers, each with individually addressable data. It was suggested that a card with the data area roughly 25 mm (one inch) wide could be able to hold 10 GB of data. The Millimetre ( American spelling: millimeter, symbol mm) is a unit of Length in the Metric system, equal to Inches redirects here To see the Les Savy Fav album see Inches. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer