Abstract: A set of colorants for printing a multi-colored image when viewed under non-visible radiation outside of the visible spectrum can include a first colorant and a second colorant. The first colorant can be capable of absorbing non-visible radiation and shifting the wavelength of the non-visible radiation to a visible wavelength, thus producing a visible color. Likewise, the second colorant can be capable of absorbing the non-visible radiation and shifting the wavelength to a second visible wavelength, thus producing a different visible color.

Abstract: Ink-jet inks and methods for security and anti counterfeiting utilities are described. The inks are fluorescent with a particular characterizing emission when illuminated with ultraviolet or other interrogating light and then fluoresce with a different characteristic upon illumination with bright light such as from a copying machine. The inks comprise a fluorescent dye, an aqueous liquid vehicle comprising water and organic solvents in sufficient amounts to achieve an ink viscosity and surface tension effective for application of the ink to a substrate in a predetermined pattern by ink-jet printing, wherein the inks are characterized in that after exposing under Xenon lamp of 3,150,000 J/m2, the fluorescent strength of the ink diluted 100 times existing between about 500 nm and about 700 nm by excitation of ultraviolet radiation, decreases by at least about 50%.

Abstract: The invention relates to a marking liquid which contains a polymer dispersion with particles which are colored with marking agent, optionally further dyes and marking agents, one or more salts of a polyvalent, in particular bi- or trivalent cation, water and optionally moisture retaining agents and further usual additives, wherein the polymer forming the polymer particles is selected from the group of polyesters, polyester amides, polymers and copolymers based on acrylate or methacrylate with a proportion of free carboxylic acid groups of less than 10% by weight, melamine-formaldehyde-sulfonamide resins and mixtures thereof.

Abstract: A fluorescent water base ink for ink-jet recording includes water, a first fluorescent dye, and a second fluorescent dye. The first fluorescent dye absorbs light in a first absorption wavelength region in an ultraviolet region to emit fluorescence, and the first fluorescent dye absorbs light in a second absorption wavelength region to emit no fluorescence. The second fluorescent dye absorbs light in an absorption wavelength region in the ultraviolet region, which is different from the first absorption wavelength region of the first fluorescent dye, to emit fluorescence. A wavelength region of the fluorescence of the second fluorescent dye is not overlapped with the first absorption wavelength region of the first fluorescent dye, but at least a part of the wavelength region of the fluorescence of the second fluorescent dye is overlapped with the second absorption wavelength region. The fluorescence intensity of the ink is increased.

Abstract: Disclosed is a phase change ink containing a fluorescent colorant that upon exposure to activating energy fluoresces such that an image that was not visible prior to exposure to the activating energy becomes visible. Also disclosed are an ink jet system and a process for authenticating a color document using the disclosed phase change ink.

Abstract: A process for printing an image on a substrate comprising applying to the substrate an ink comprising a compound of Formula (1) or a salt thereof: wherein: R1 and R2 are each independently H or a substituent; each X and Y independently is a substituent; and a and b are each independently 0, 1, 2, 3 or 4. The compounds used in the process have particularly good ozone fastness and are suitable for preparing inks which can be ink jet printed.

Abstract: An ink for ink-jet recording includes a solvent dye in which a xanthene structure and a phthalide structure are spiro bound to each other. When the ink is stored in an ink cartridge containing a polyurethane foam and ink-jet recording is performed, a stable printing density may be achieved and changes in hue may be avoided.

Abstract: Sulfur-containing phosphor powders, methods for making phosphor powders and devices incorporating same. The powders have a small particle size, narrow particle size distribution and are substantially spherical. The method of the invention permits the continuous production of such powders. The invention also relates to products such as display devices incorporating such phosphor powders.

Abstract: A fluorescent water base ink for ink-jet recording contains a first fluorescent dye and a second fluorescent dye. The first fluorescent dye has a first ultraviolet absorption wavelength region in an absorption spectrum and a first fluorescence emission wavelength region in a fluorescence spectrum. The second fluorescent dye has a second ultraviolet absorption wavelength region which is different from the first ultraviolet absorption wavelength region in an absorption spectrum and a second fluorescence emission wavelength region in a fluorescence spectrum. The first fluorescent dye further has an absorption wavelength region which is different from the first ultraviolet absorption wavelength region and which overlaps at least a part of the second fluorescence emission wavelength region.

Abstract: Disclosed is a photochromic golf ball with a one- or multi-piece structure, which comprises a photochromic compound. The photochromic golf ball reversibly changes between two different color states according to exposure to U.V. radiation associated with direct sunlight. The photochromic golf ball is white when it is shielded from direct sunlight, but changes in color when it is directly exposed to direct sunlight. In a golf ball structure having a core, an outer cover, and a transparent coating, the photochromic compound is present either in the outer cover or the transparent coating.

Abstract: Fluorescent pigment compounds comprising aryl-ureido benzoxazinone compounds of the general formula (I): wherein R1 is an substituted or unsubstituted aryl group, R2 and R3 are each independently selected from an H atom, an alkyl group, an alkoxy group, an alkylcarboxy group and a halogen atom, X is a carbon or sulfur atom and n is an integer of 1 or more. Many of the compounds of this class produce a yellow, generally deep yellow, emission at wavelengths of about 560 to about 585 nm when excited by an appropriate UV source. These compounds produce fluorescence making them useful as fluorescent pigments, those compounds providing emission wavelengths within the range of from about 560 to about 585 or higher when excited by a UV source are particularly useful. Those compounds having this emission spectra for the compounds makes these compounds particularly useful as pigments in security applications, particularly as pigments for use in security inks and fibers.

Abstract: A fluorescent water base ink for ink-jet recording contains a fluorescent dye having a xanthene skeleton, and a glycol. In the fluorescent dye, the difference in hydrophilic index log P is not less than 2.6 between a substituent bonded to C-9 carbon atom of the xanthene skeleton and other portion of the fluorescent dye than the substituent bonded to the C-9 carbon atom. The glycol has a distance between hydroxyl groups substantially equivalent to or longer than an interatomic distance between atoms directly bonded to C-3 and C-6 carbon atoms of the xanthene skeleton of the fluorescent dye, respectively. It is assumed that the glycol is coordinated with the xanthene skeleton in a bridge form to increase the fluorescence intensity by increasing the electron density of the xanthene skeleton. The ink having high fluorescence intensity and in which the fluorescence intensity is not lowered in a time-dependent manner is provided.

Abstract: A process for the preparation of organic pigments with enhanced fluorescence, which process comprises treating said pigments with a surfactant, and to the fluorescent organic pigments obtained by said process. The pigments according to the present invention can be used in marking applications, wherein durable fluorescence is required.

Abstract: In accordance with one embodiment of the present invention, a colorant in an ink jet ink formulation is disclosed. The colorant comprises an organic dye chromophore with at least one functional group Y containing one or more primary, secondary or tertiary amino groups, which in the presence of an acid provides a water soluble, cationic ink jet ink colorant with increased water fastness when applied to paper.

Abstract: Disclosed is an ink composition suitable for ink jet printing comprising a luminescent compound, a solvent, and an energy active compound, and optionally a non-luminescent colorant. The energy active compound, when exposed to energy, generates one or more active species that can react with the luminescent compound to alter one or more of the characteristics of the luminescent compound. The luminescent compound can be colored or colorless. Also disclosed is a method for marking substrates comprising providing a mark comprising a luminescent compound and an energy active compound. Further disclosed is a jet ink composition suitable for printing on substrates authentication or security marks which can be rendered unreadable. The luminescence of the mark is quenched and the visible color is changed when irradiated with a light.

Abstract: The present invention provides a fluorescence ink having a high fluorescence intensity, and an ink jet recording method using the same. The ink contains a first fluorescent coloring material that emits fluorescence at a predetermined fluorescence wavelength to be used for measurement or determination with excitation at a predetermined excitation wavelength, a second fluorescent coloring material that emits fluorescence on excitation at the predetermined excitation wavelength, where the excitation spectrum of the first coloring material in the ink to obtain the fluorescence at the predetermined emission wavelength has a peak wavelength range next to the predetermined fluorescence wavelength, and the emission fluorescence spectrum of the second coloring material has an emission wavelength region substantially including at least the above peak wavelength range.

Abstract: The present invention relates to fluorescent diketopyrrolopyrroles (“DPPs”) of the formula characterized in that that at least two adjacent substituents R5 to R11 form an aromatic or aliphatic fused ring system, or at least one substituent R5 to R11 is cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, a hydroxyl group, a mercapto group, alkylthio, an aryl thioether group, a heterocyclic group, halogen, haloalkyl, haloalkenyl, haloalkynyl, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an ester group, a carbamoyl group, a nitro group, a silyl group, a siloxanyl group, a substituted or unsubstituted vinyl, arylamino or diarylamino group; a process for their preparation and their use for the preparation of inks, colorants, pigmented plastics for coatings, non-impact-printing material, color filters, cosmetics, or for the preparation of polymeric ink particles, toners, dye lasers and electroluminescent devices.

Abstract: The present invention pertains to an improved marking fluid that contains a sugar and/or a sugar alcohol, as well as methods for their manufacture.

Abstract: In general, a smear-resistant ink composition according to the present invention comprises: (1) water; (2) at least one glycol selected from the group consisting of diethylene glycol, ethylene glycol, glycerol, and propylene glycol; (3) a pyrrolidone selected from the group consisting of 2-pyrrolidone and 3-pyrrolidone; and (4) at least one colorant that produces a detectable fluorescent color when the ink composition is applied to paper. Preferably, the pyrrolidone is 2-pyrrolidone. In one preferred embodiment, the at least one glycol comprises diethylene glycol and ethylene glycol. In another preferred embodiment, the at least one glycol comprises diethylene glycol, ethylene glycol, and propylene glycol. The composition can comprise other ingredients, such as a basic color stabilizer, a resin, a resin modifier that is a carbonate salt, a biocide, and a nonionic surfactant. The colorants can be formulated to produce a pink, yellow, blue, green, purple, or orange color; other colors are possible.

Abstract: Water-based invisible red fluorescent inks provide machine-readable, inverse contrast invisible images and can be printed using conventional ink jet printers. The inks employ rare earth complexed ligand fluorophores having narrow excitation and emission spectra. In one embodiment the images are printed with an ink comprising water and a water-soluble organic fluorescent fluorophore, which when printed and dried on paper is invisible to the eye and fluoresces in the green to infrared range, e.g., from about 550 to 1200 nm, when irradiated with short wave length UV radiation, e.g., from 230 nm to 280 nm. The highly specific excitation and emission rates, coupled with a high inverse contrast on papers of all colors, makes them particularly useful as ink jet inks for postal and other purposes.

Abstract: The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.

Abstract: A latent or “invisible ink” security marking formulation is provided using a phosphor with distinct emissions characteristics including visible emission due to excitation at a particular invisible wavelength. An insoluble inorganic phosphor with this or a similarly distinct emission characteristic is milled to a small particle size, preferably less than one micron particle diameter, and is combined with a carrier at very low pigment concentration, for example one percent by weight of the ink formulation. Preferably the pigment is cropped to resin particles in a binder. This ink formulation is diluted by a volatile solvent and applied using a conventional inkjet printer of the type used to mark codes on packages and labels. To test for security purposes the printing is irradiated and a response according to the predetermined characteristic is noted (or not noted) to detect security information.

Abstract: A coating composition includes a material adapted to form a coating; and a material that fluoresces when exposed to U.V. light or the material adapted to form a coating contains a U.V. blocker disposed on a U.V. indicator. A kit containing a U.V. indicator and material adapted to form a coating containing a U.V. blocker. Methods of coating a substrate with the coating compositions are also disclosed.

Abstract: A water-based, aerosol marking composition that adheres to a variety of surfaces but is removable by mechanical rubbing with a dry cloth or by washing with water is provided. The composition comprises 10 to 50% by weight water; 5 to 50% by weight of a solvent selected from the group consisting of a C6 to C15 aliphatic solvent, an aromatic solvent comprising 10 or fewer carbon atoms, an ether, and an alcohol, or combinations thereof; 0.1 to 4% of an emulsifier having a hydrophile to lipophile balance of from 1.8 to 16.7; a marking agent; and 10 to 45% propellant. In a preferred embodiment the composition lacks or contains only trace amounts of an alkyd-based drying oil, polyvinylpyrrrolidone, or polyvinyl alcohol, or another agent that serves as an adhesive for the pigment particles. In certain embodiments, the composition comprises an inorganic filler and from 0.05% to 3% surfactant.

Abstract: A fluorescent ink composition comprising functionalized fluorescent nanocrystals, an aqueous-based ink carrier comprising water or a water-based solution, and a binder.

Abstract: The present invention provides for functionalized fluorescent nanocrystal compositions and methods for making these compositions. The compositions are fluorescent nanocrystals coated with at least one material. The coating material has chemical compounds or ligands with functional groups or moieties with conjugated electrons and moieties for imparting solubility to coated fluorescent nanocrystals in aqueous solutions. The coating material provides for functionalized fluorescent nanocrystal compositions which are water soluble, chemically stable, and emit light with a high quantum yield and/or luminescence efficiency when excited with light. The coating material may also have chemical compounds or ligands with moieties for bonding to target molecules and cells as well as moieties for cross-linking the coating.

Abstract: A resin based fluorescent marking stain is formulated from a resin present in a concentration of about 10 percent to about 20 percent of the marking stain, an active solvent for and compatible with the resin present in a concentration of about 65 percent to about 85 percent of the marking stain, a plasticizer present in a concentration of about 1.0 percent to about 5.0 percent of the marking stain, an optical brightener present in a concentration of about 0.5 percent to about 5.0 percent of the marking stain and a fluorescent dye present in a concentration of about 0.1 percent to about 5.0 percent of the marking stain.

Abstract: The present invention provides a fluorescence ink having a high fluorescence intensity, and an ink jet recording method using the same. The ink contains a first fluorescent coloring material that emits fluorescence at a predetermined fluorescence wavelength to be used for measurement or determination with excitation at a predetermined excitation wavelength, a second fluorescent coloring material that emits fluorescence on excitation at the predetermined excitation wavelength, where the excitation spectrum of the first coloring material in the ink to obtain the fluorescence at the predetermined emission wavelength has a peak wavelength range next to the predetermined fluorescence wavelength, and the emission fluorescence spectrum of the second coloring material has an emission wavelength region substantially including at least the above peak wavelength range.

Abstract: An article is marked with image indicia for authentication, information, or decoration by providing a plurality of inks having a plurality of fluorescence colors when exposed to excitation energy, separating colors of the image indicia into a plurality of image levels in accordance with the fluorescence colors of the inks, and printing each image level in mutual registration on the article using the corresponding ink. The image printed with each ink may be substantially invisible under illumination within the visible spectrum. The invisibly printed images have multiple authentication features, including the use of covert UV-fluorescent materials, IR-fluorophores, microparticles, and other chemical taggants. Ink compositions, methods for making the inks, and methods and apparatus for using the inks are also disclosed.

Abstract: The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.

Abstract: Non-green anti-Stokes luminescent material, comprising the elements Ln, erbium (Er) and ytterbium (Yb), Ln representing at least one element which is selected from the group consisting of yttrium (Y), gadolinium (Gd), scandium (Sc) and lanthanum (La), a process for its production and its use.

Abstract: The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.

Abstract: Disclosed are sets of ink components, and ink compositions, useful for printing markings, on security documents, that are relatively resistant to counterfeiting. Also disclosed are the security documents formed, a method of printing and a method of authenticating the printed material. The markings, formed of the ink compositions have a spectral response that deviates from a predicted spectral response when linearly additively combining spectral responses of components of the ink composition, so that it becomes difficult to reverse-engineer the ink composition from the markings. Use of plural different markings, with each marking being a microdot, increases difficulty in counterfeiting. By forming a template of spectral responses of the original pattern, spectral responses of a pattern on an unknown document can be compared to the spectral responses on the template for determining whether the unknown document is authentic. Formation of the markings is facilitated using an inkjet printer.

Abstract: A water-based security printing ink is provided with two means of security. The use of a variable light absorbing and/or transmitting pigment or dye is a first security and a water repelling agent is provided as a second security. Visible images can be generated from the printed ink upon exposure to UV or infrared light. The water repelling agent renders the image waterproof and differentiates the printed image from the substrate, which allows the image to be detected upon exposure to water or other aqueous mixture. Suitable inks can be used in conventional printing methods, such as jet printing, lithography, offset printing and impact printing. Also provided are substrates imaged with these security printing inks.

Abstract: Water-based invisible red fluorescent inks provide machine-readable, inverse-contrast invisible images and can be printed using conventional ink jet printers. The inks employ rare earth complexed ligand fluorophores having narrow excitation and emission spectra. In one embodiment the images are printed with an ink comprising water and a water-soluble organic fluorescent fluorophore, which when printed and dried on paper is invisible to the eye and fluoresces in the green to infrared range, e.g., from about 550 to 1200 nm, when irradiated with short wave length UV radiation, e.g., from 230 nm to 280 nm. The highly specific excitation and emission rates, coupled with a high inverse contrast on papers of all colors, makes them particularly useful as ink jet inks for postal and other purposes.

Abstract: Europium compounds represented by the general formula (1) and water-base ink compositions containing the same: 1

Abstract: The present invention pertains to an improved marking fluid that contains a sugar and/or a sugar alcohol, as well as methods for their manufacture.

Abstract: Disclosed is a blue luminous ink composition comprising a luminous compound represented by the formula: wherein R1 is a group selected from the group consisting of a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, an alkoxyl group having from 1 to 4 carbon atoms and a halogen atom, R is a group selected from the group consisting of a fluorine-comprising alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 4 carbon atoms, a substituted or unsubstituted aralkyl group having from 7 to 10 carbon atoms and a substituted or unsubstituted aryl group having from 6 to 12 carbon atoms, M is a two-valent or three-valent metal, provided rare-earth metal and alkaline earth metal (IIa group) are eliminated, and n is an integer of 2 or 3. The blue luminous ink composition exhibits satisfactory emission intensity under ultraviolet irradiation.

Abstract: The colored liquid composition of the invention for a highlighter comprises a coloring element and water, the water content by weight lies in the range 10% to 30%. In addition, it comprises at least 40% of a liquid component having surface tension greater than 40 mN/m. In a variant, the coloring element is a tracer solvent having a fluorescent appearance under basic pH, in particular hydroxypyrenetrisulfonic acid, the pH of the composition lying in the range 8 to 9, and the component having surface tension greater than 40 mN/m is triethanolamine. Under such circumstances, the composition contains an acid to neutralize the triethanolamine in part in order to obtain the basic pH, for example hydrochloric acid.

Abstract: The present invention provides ink for an ink-jet printer containing a fluorescent compound which emits fluorescence by ultraviolet irradiation, a surfactant, and water. The ink can satisfy all points of quick-drying property of the ink after printing, print quality, and change in the hue, lightness, and chroma of the print part by irradiation of light source. A fluorescent compound which has absorption in the visible light range and which emits fluorescence by ultraviolet irradiation and a fluorescent compound which has no absorption in the visible light range and which emits fluorescence, by ultraviolet irradiation, with a hue different from that of the fluorescence emitted from the aforementioned fluorescent compound under visible light are mixed.

Abstract: There is provided an aqueous fluorescent ink that contains an emulsified colored resin and a water-soluble compound having ethylene oxide units that is solid at 25° C.

Abstract: An imaging composition comprises a mixture of a fluid and a functional material; wherein the fluid is compressed and the functional material is an electroluminescent material which is dissolved, dispersed and/or solubilized in the compressed fluid; and wherein the mixture is thermodynamically stable or thermodynamically metastable or both.

Abstract: A fluorescent marking stain for marking items is formulated from a resin present in a concentration of about 1 percent to about 5 percent of the stain, an active solvent for and compatible with the resin present in a concentration of about 40 percent to about 50 percent of the stain, a dye solvent present in a concentration of about 20 percent to about 30 percent of the stain, a diluent present in a concentration of about 10 percent to about 20 percent of the stain, an adhesion promoter present in a concentration of about 1 percent to about 5 percent of the stain, an optical brightener present in a concentration of about 1 percent to about 5 percent of the stain and a fluorescent dye present in a concentration of about 0.2 percent to about 5 percent of the stain. A marking pen for use with the marking stain is also disclosed.

Abstract: In general, a smear-resistant ink composition according to the present invention comprises: (1) water; (2) at least one glycol selected from the group consisting of diethylene glycol, ethylene glycol, glycerol, and propylene glycol; (3) a pyrrolidone selected from the group consisting of 2-pyrrolidone and 3-pyrrolidone; and (4) at least one colorant that produces a detectable fluorescent color when the ink composition is applied to paper. Preferably, the pyrrolidone is 2-pyrrolidone. In one preferred embodiment, the at least one glycol comprises diethylene glycol and ethylene glycol. In another preferred embodiment, the at least one glycol comprises diethylene glycol, ethylene glycol, and propylene glycol. The composition can comprise other ingredients, such as a basic color stabilizer, a resin, a resin modifier that is a carbonate salt, a biocide, and a nonionic surfactant. The colorants can be formulated to produce a pink, yellow, blue, green, purple, or orange color; other colors are possible.

Abstract: A fingerprint capture or processing apparatus incorporates a casing defining a sealable chamber, a first support in the chamber for holding a source of a chemical fingerprint fixative agent, a second support in the chamber for holding an article to be tested for fingerprints, a filtration system connected to the chamber for removing contaminants from air in the chamber, and an air circulation assembly operatively connected to the casing for circulating air from the chamber and through the filtration system. Preferably, the air circulation assembly is a closed system, ensuring that no contaminants will be spilled to the ambient atmosphere prior to complete cleansing of the air inside the casing. A humidity control device may be connected to the air circulation assembly for modifying a humidity level in the chamber to a predetermined relative humidity, thus optimizing effectiveness of the chemical fingerprint fixation agent.

Abstract: A fluorescent ink composition comprising functionalized fluorescent nanocrystals, an aqueous-based ink carrier comprising water or a water-based solution, and a binder.

Abstract: The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.

Abstract: The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.

Abstract: An organic or organoelement, linear or branched, monomeric or polymeric composition of matter having a Raman-active component in the form of particles. The particles having a maximum dimension of 50 &mgr;m. The Raman-active compound is applied to a substrate. When the Raman-active compound is exposed to a laser light wavelength which is batochromically well beyond a spectral region of maximum absorbance of said Raman-active compound, Raman scattering can be detected.

Abstract: The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.