The term ‘hologram’ is derived from two Greek words: ‘holos’ meaning whole or complete and ‘graphos’ meaning an image. The term therefore describes a recorded image which is complete, in that it shows the whole volumetric space of...

Hot foiling (stamping)

A method of transferring a foil from one substrate to another by the application of heat and pressure.

Hot-melt adhesive

An adhesive that is solid at room temperature and becomes liquid when heated. Used to bond two surfaces when cool.

Hydrogen bonding

A chemical bond in which a hydrogen atom of one molecule is attracted to an electronegative atom (usually nitrogen or oxygen) in the same or a different molecule. Typically, the properties of water are an example of hydrogen bonding.

Heat transfer printing

A method of lamination whereby heat is used to transfer print from one substrate to another. Most of the US tax stamps are applied by this method.