Water based inks containing near infrared fluorophores

An ink composition comprising:

• A. between about 1 and 10 weight percent of at least one water-dissipatable polyester comprising:
• (i) monomer residues of at least one dicarboxylic acid;
• (ii) about 4 to 25 mole percent, based on the total of all acid, hydroxy and amino equivalents, of monomer residues of at least one difunctional sulfomonomer containing at least one sulfonate group bonded to an aromatic ring where the functional groups are hydroxy, carboxyl, carboxylate ester or amino;
• (iii) monomer residues of at least one diol or a mixture of diol and a diamine;
• and optionally,
• (iv) monomer residues of at least one difunctional monomer reactant selected from the group consisting of hydroxycarboxylic acids, amino carboxylic acids and aminoalkanols;
• provided that at least 20 percent of the groups linking the monomeric units are ester linkages;
• said water-dissipatable polyester having from about 0.1 ppm by weight to about 10% by weight of a thermally stable near infrared fluorophoric compound copolymerized therein;
• B. between about 5 and 75 weight percent of at least one aliphatic humectant;
• C. between about 0 and 15 weight percent of at least one lower aliphatic alcohol of no more than 3 carbon atoms;
• D. water and optionally up to about 2 weight percent of one or more additives;
• wherein the weight percentages of components A-D equal 100%.