Microparticle taggant systems

A process for marking an article by applying thereto a taggant, a marking formulation comprising a taggant, or an article marked with a taggant, wherein the taggant comprises a microparticle having three or more distinguishable marker layers corresponding to a predetermined numeric code, said marker layers comprising at least one datum marker layer coded to include place information and at least two value marker layers coded to specify a value within the place, the at least one datum marker layer being readily distinguishable from the value marker layers and functioning to identify an orientation of the value marker layers.

A process for marking an article by applying thereto a taggant, a marking formulation comprising a taggant, or an article marked with a taggant, wherein the taggant comprises a microparticle having two distinguishable marker layers corresponding to a predetermined numeric code, the combination of said two marker layers determining both numeric place and a value within said place in a binary numbering system.

A process for marking an article by applying thereto a taggant, a marking formulation comprising a taggant, or an article marked with a taggant, wherein the taggant comprises a particle having two distinguishable marker layers of different color characteristics wherein the paired combination of color characteristics provided by said two layers codes for a numeric value.

A method for marking an object with a taggant comprising a plurality of coded taggant particles, the method comprising:

• providing the plurality of taggant particles characterized in that it comprises at least two different elements on at least two different particles, the elements represented by said different particles forming an element series, each element in said series conveys numerical value and position information, and the combination of different elements employed in said series, taken together, provides a coded number comprising a plurality of values at a plurality of positions of a predetermined numerical code, and
• applying the plurality of particles to the object.