Articles with porous particles for security purposes

A varnish or ink comprising one or more porous particles, wherein

• each porous particle comprises a polymer that provides a continuous solid phase including an external particle surface, and at least first and second discrete pores that are isolated from each other and dispersed within the continuous solid phase,
• and each porous particles further comprising a first marking material that is present within only the volume of the first discrete pores, and a second marking material that is present within only the volume of the second discrete pores, which first and second marker materials are detectably different the porous particle having a mode particle size of at least 2 μm and up to and including 75 μm.

A formed polymer or glass article that comprises one or more porous particles, wherein

• each porous particle comprises a polymer that provides a continuous solid phase including an external particle surface, and at least first and second discrete pores that are isolated from each other and dispersed within the continuous solid phase,
• and each porous particle further comprises a first marking material that is present within only the volume of the first discrete pores, and a second marking material that is present within only the volume of the second discrete pores, which first and second marker materials are detectably different the porous particle having a mode particle size of at least 2 μm and up to and including 75 μm.