polymeric retention aids it is believed that these modified polymers will adhere to treated and non treated cellulose fibers fluorescent nanoparticles can also be attached to cellulose fibers to yield tagged fibers an advantage of being attached to fibers is that the fluorescent nanoparticles are less likely to be removed in the de watering process attachment can be accomplished through covalent bonding adsorption and physical immobilization quantum dots can also be encapsulated with polymers with specific physical properties as described in u s pat no 7 081 489 to chen et al which is incorporated herein by reference for paper applications suitable polymers are preferably water insoluble thermoplastics which include but are not limited to polyamides polycarbonates polyalkenes polyvinyl ethers polyglycolides cellulose ethers e g hydroxy propyl cellulose hydroxy propyl methyl cellulose and hydroxy butyl cellulose polyvinyl halides polyglycolic acid and polylactic acid a further embodiment of the inventive process provides on line measurements of one or more components in coated paper techniques for coating paper sheets are described in u s pat no 7 255 918 to watanabe et al and u s pat no 6 074 483 to belotserkovsky et al which are incorporated herein by reference fig3 shows base sheet 84 that has an upper coating 82 and lower coating 86 the thickness for any or all three layers can be measured by incorporating appropriate species of fluorescent nanoparticles and detecting their emission spectra for example in the production of high gloss paper.