Machine-readable codes are essential where security and accurate reading of information are of high importance. Whilst the barcode is ideal for small quantities of information to be machine read off high contrast surfaces, for more demanding applications a 2-d code like a Data Matrix code is required. These codes can store up to 2000 characters and their size can be from 25 microns to over 300 mm square. Curved and uneven surfaces, highly reflective surfaces and materials that give a low contrast can be marked by laser with a Data Matrix code. These codes also have a level of redundancy that allows a successful read even when partly damaged.

More sophisticated readers than standard barcode readers are required and the lighting of the mark is critical and most readers have their own lighting. In military and medical applications, particularly on stainless steel and curved surfaces, the Data Matrix code has become the standard.

FIMARK has provided barcode labels and nameplates to all sectors of industry and has recently been working with a UK supplier to the US Navy along with a manufacturer of UID verification software. Unique Identifier codes (a special form of Data Matrix code) and their validation certificates are becoming compulsory for any supplier to the US military.
The website www.acq.osd.mil/dpap/UID/datamatrix.htm gives further information.

The flexibility of laser marking allows serial numbers and variable information to be added to almost any surface in the form of a machine-readable code. Software converts data that can be inputted from a text file into the graphical format of a barcode or Data Matrix code. The laser parameters are selected to maximise readability and are optimised for each material. For example on steel the surface might be turned black and with aluminium the surface would be etched.