Security papers (use watermarks), e.g. money

Security pantograph – this is an instrument used for copying, enlarging, or reducing line drawings that are used as a security device on a printed record or form. Hidden words, company logos or designs, even forensic information appears when the document is photocopied or scanned, preventing unauthorized duplications – and authentication has never been simpler.

Micro printing – an area on the document can be imprinted with microscopic words that appear to the casual reader as a solid line.  On the originals, the words can be read under magnification.  On copies, the micro printing is unreadable.  E.g. money – has micro printing on it in order to stop counterfeit money being made

Thermo chromic ink – the use of heat sensitive ink will cause a change in color of text or will cause text to disappear when heat is applied to the ink.  Example – mood ring changes color according to temperature of your body.

Bleed through numbering – when a specially inked ribbon comes into contact with paper, the numbers appearing on the right side of the document, such as on a check, bleed through and appear red on the reverse side.