Abstract: Seamless, sleeve-shaped dry and wet lithographic printing members that can be recycled after use are disclosed, along with methods for their manufacture and use. The members include a strong, durable, hollow cylinder or sleeve that is attached to the plate mandrel or cylinder jacket of an offset printing press or platemaking apparatus. Surrounding the sleeve is a layer of a material, preferably polymeric in nature, which is characterized by efficient, ablative absorption of laser radiation, as well as other layers that facilitate imaging and subsequent printing. A layer disposed beneath the ablatable layer reflects unabsorbed imaging radiation back into the ablatable layer.

Abstract: The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process comprising the steps of exposing and developing an imaging element comprising in the order given on a hydrophilic surface of a support (i) an image receiving layer and (ii) a photosensitive layer comprising a photosensitive silver halide emulsion, removing the layer(s) on top of the image receiving layer thereby exposing the imaged surface of the support and treating said exposed imaged surface of the support with a finisher having a temperature between 30.degree. C. and 60.degree. C.

Abstract: The present invention discloses the use of rubber and surfactant to enhance the durability and resolution of on-press developable lithographic printing plates. The rubber is preferably incorporated into a photoresist as discrete particulate rubber. To ensure a uniform and stable dispersion, the rubber is suspended in the photoresist by means of a surfactant having an HLB approximately between 7.0 and 18.0.

Abstract: The present invention provides an improvement of the direct lithographic printing plate making process using ink-jet printing, which provides a printing plate having excellent resolution. Accordingly, the present invention provides an improvement of a process for producing a lithographic printing plate comprising selectively forming a light transmittable oxygen barrier film on a photopolymerizable layer of a photosensitive plate, exposing to light and then removing uncured portion on which the oxygen barrier film is not covered, wherein a protective layer which is capable of transmitting oxygen gas and the light to cure the photopolymerizable layer is formed on the photopolymerizable layer, a photosensitive plate therefor and an aqueous ink composition therefor.

Abstract: Disclosed is a method for preparation of a printing plate by an electrophotographic process comprising forming a toner image on an electrophotographic light-sensitive element by an electrophotographic process. A peelable transfer layer is provided mainly containing a resin (A) capable of being removed upon a chemical reaction treatment on the toner image. The toner image is transferred together with the transfer layer onto a primary receptor. The toner image together with the transfer layer is then transferred from the primary receptor onto a receiving material having a surface which is capable of providing a hydrophilic surface suitable for lithographic printing at the time of printing. The transfer layer on the receiving material is removed by the chemical reaction treatment.

Abstract: In order to permit a printing form to be produced by laser-induced thermotransfer in a simple manner that can be integrated into the printing machine, without the gases which arise during laser imaging detectably disturbing the transfer of material from the transfer foil, i.e., the image quality, a strip-type transfer foil with a strip width that is small relative to the printing form width is used. During imaging, this transfer foil is conveyed continually between the printing form and the laser beam, close to the printing form surface, and is thereby moved simultaneously and synchronously with the movement of the laser beam across the printing form width.

Abstract: Surface reforming of a polymeric article containing a polymerizable compound is effectively performed by polymerizing the polymeric article in contact with a surface reforming medium because the transfer of the material constituting the surface reforming medium to the polymeric article is enhanced by the polymerization. The surface reforming can be performed locally selectively, i.e., imagewise. The remaining un-polymerized part may be subjected to further surface reforming, e.g., by using another type of surface reforming medium or attachment of powder, to provide an enhanced contrast of surface property. Such an enhanced contrast of surface property can be effectively used, e.g., for production of a printing plate.

Abstract: For producing fine printing patterns on large serigraphical printing frames it is possible to apply an exposure through correspondingly large film areas, but it is cheaper to make use of a successive line-by-line exposure with the use of a modulated light or laser beam, which is caused to sweep across an emulsion coated printing frame surface from an oscillating deflection mirror. The beam (20), in its outermost positions, will be directed obliquely towards the surface (14), and if the latter changes its distance from the oscillating mirror (48) the exposure lines (16) will thus be correspondingly shorter or longer, whereby the printing pattern may be distorted.

Abstract: Laser-imageable lithographic printing members have rigid base supports that confer strength and rigidity. The supports may reflect imaging radiation so that radiation from an imaging pulse that passes through an imaging layer is returned to that layer, thereby augmenting the effective energy flux density. In the case of thermally conductive (e.g., reflective metal) base supports, heat is concentrated in the imaging layer by an underlying insulating layer interposed between the imaging layer and the base support.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: A printing method for an in situ plate production process in which a photosensitive plate blank having a polymerization layer between a support and a release film is fixed to a plate cylinder either before or after forming a polymerization-nonpolymerization pattern in the polymerization layer. The polymerization layer can be a thermal development-type photosensitive layer for forming the pattern. The release film is then peeled apart from the plate blank to leave a printing plate on the plate cylinder, which can be used for printing and for an inking step. The printing pattern of the plate can be formed by selective removal of the unpolymerized part or by selective transfer of the release film to the polymerized part of the polymerization layer.

Abstract: Lithographic printing constructions and methods of imaging them. The constructions include a grained-metal substrate, a protective layer that can also serve as an adhesion-promoting primer, and an ablatable oleophilic surface layer. In operation, imagewise pulses from an imaging laser interact with the surface layer, causing ablation thereof and, probably, inflicting some damage to the underlying protective layer as well. The imaged plate may then be subjected to a solvent that eliminates the exposed protective layer, but which does no damage either to the surface layer or to the unexposed protective layer lying thereunder.

Abstract: Lithographic printing plates suitable for imaging by means of laser devices that emit in the near-infrared region. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: A method for preparing a lithographic printing plate comprises imagewise exporting a PS plate comprising an aluminum substrate having an anodized layer and a light-sensitive layer applied on one side of the substrate and then developing the PS plate with a developer comprising an aqueous solution of an alkali metal silicate, while compensating changes in the developer due to the development of the PS plate by supplementing, to the developer, a replenisher comprising an aqueous solution of an alkali metal silicate, wherein the PS plate is provided with a coating layer containing an organic polymeric compound on the back face and the replenisher is an aqueous solution of an alkali metal silicate having a ratio: [SiO.sub.2 ]/[M.sub.2 O] (wherein [SiO.sub.2 ] means molar concentration (mol/l) of SiO.sub.2 and [M.sub.2 O] is molar concentration (mol/l) of oxide M.sub.2 O of an alkali metal (M)) ranging from 0.3 to 1.0 and an SiO.sub.2 content ranging from 0.5 to 4.0% by weight.

Abstract: Seamless, sleeve-shaped dry and wet lithographic printing members that can be recycled after use along with methods for their manufacture and use. The members include a strong, durable, hollow cylinder or sleeve that is attached to the plate mandrel or cylinder jacket of an offset printing press or platemaking apparatus. Surrounding the sleeve is a layer of a material, preferably polymeric in nature, which is characterized by efficient, ablative absorption of laser radiation, as well as other layers that facilitate imaging and subsequent printing.

Abstract: A device for creating a printing pattern on an endless form sleeve utilizes a pattern forming head that is cooperatively positioned with an outer surface of an endless, sleeve. The sleeve has an inner ply of a ferromagnetic material and is supported in part by a support cylinder which may also be magnetic. A sleeve tensioning assembly is used to tension that part of the endless sleeve which is not supported by the cylinder.

Abstract: A thermosensitive recording material comprising a recording layer formed on a substrate and a coating film layer formed thereon, wherein the recording layer is of a bilayer structure composed of a first thermosensitive layer on the side of the lower layer and a second thermosensitive layer on the side of the upper layer and particles are dispersed in at least one of the first and second thermosensitive layers. An original plate for lithographic printing can be produced from a combination of an ink-philic resin and an ink-repelling resin as the compositional materials of such thermosensitive layers. Besides, thermosensitive, recording materials for magnetic recording, thermosensitive materials for electrostatic recording, thermosensitive recording materials for colored image recording and the like, can be generated through a variety of modifications of the compositional materials.

Abstract: According to the present invention a method is provided for obtaining an image comprising the steps of:information-wise exposing an imaging element comprising on a support a photosensitive layer containing a photopolymerizable composition and a base layer located between said support and said photosensitive layer and wherein said base layer is contiguous to said photosensitive layer and comprises a polymer containing polymerizable ethylenically unsaturated groups andtransferring upon heating the non-hardened or insufficiently hardened parts of said photosensitive layer to an image receiving material. When the image receiving material contains a hydrophilic surface a lithographic printing plate can be obtained.

Abstract: A lithographic printing plate for use on a printing press, with minimal or no additional processing after photoexposure, comprises a printing plate substrate; a photosensitive hydrophilic layer having a polymeric hydrophilic binder and a photopolymerizable, photocrosslinkable or photorearrangeable compound capable of promoting insolubilization or hardening in areas of photoexposure; and a photosensitive hydrophobic layer having a polymeric hydrophobic binder and a photopolymerizable, photocrosslinkable or photorearrangeable compound capable of promoting insolubilization or hardening in areas of photoexposure.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: To compensate for tolerances and variations in tolerances in a recording system in which a thermal transfer foil is passed between a image recording element (3) and a printing form carrier (1), the thermal transfer foil, for example of a polyester base (9), has an intermediate layer (8) applied thereto on which a meltable substance layer (7, 7'), for example on a polyethylene base, is located. The intermediate layer (8) is thermally volume expandable, by including therein either a foaming agent or moisture or other gas which, upon application of heat, causes foaming or the formation of gas or steam bubbles to expand its volume. Tolerances 6 of up to about 1 mm, thus, can be compensated and pressure variations and surface variations between the thermal image recording element (3) and the form carrier (1) are no longer critical.

Abstract: The present invention provides a method for making a lithographic printing plate requiring no dampening liquid comprising the steps of:image-wise exposing using a laser beam a heat mode recording material comprising on a support having an oleophilic surface (i) a recording layer having a thickness of not more than 3 .mu.m and containing a substance capable of converting the laser beam radiation into heat and (ii) a cured oleophobic surface layer and wherein said recording layer and oleophobic surface layer may be the same layer;rubbing the exposed heat mode recording material thereby removing said oleophobic surface layer in the exposed areas so that the underlying oleophilic surface is exposed andavoiding the swelling of said oleophobic surface layer by carrying out said rubbing without the use of a liquid or with the use of a non-solvent for said oleophobic surface layer.

Abstract: Techniques for imaging lithographic printing members responsive to the output of laser devices. Laser output passes through at least one discrete layer and ablates one or more underlying layers, resulting in an imagewise pattern of features on the printing member. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: A direct-to-press imaging system for use in lithographic printing wherein a master-image printing cylinder is used with separate application of ink and water onto its surface to enable repetitive conveyance of image-formatted ink films onto substrates for printing purposes. The imaging system includes a master-image printing cylinder adapted for receiving a hydrohilic coating layer on its surface and a device for laying down a uniform layer of hydrophilic material on the surface of this cylinder. An apparatus is also provided for applying oleophilic materials in image-formatted patterns on top of the layer of hydrophilic material on the master-image printing cylinder to form a printing structure having separate hydrohilic and oleophilic areas of the format to be printed.

Abstract: To remove hydrophobic particles from the surface of a hydrophilic printing plate, particularly when the printing plate is used in offset printing, an ionized reactive gas is conducted to the surface of the printing plate, and applied thereto, to cause the hydrophobic particles to form volatile reaction products, which are then removed by suction. The gas can be generated either in a burner, preferably supplied with an oxygen/hydrogen mixture, emitted from nozzles spaced between 10 to 50 mm from the printing plate, in which the printing plate and nozzle are relatively moved at a rate of about 20 mm/sec; or, alternatively, the ionized gas is generated in form of a plasma by a plasma generator, for example a magnetron, operating at 2.45 GHz, which plasma is conducted to the surface of the printing plate in a reaction chamber which is physically sealed with respect to the printing plate, so that the reaction with the hydrophobic particles can there occur.

Abstract: Grained, anodized and hydrophilized lithographic printing plates which have a negative or positive working radiation-sensitive coating, are exposed and are developed in an aqueous alkaline solution, are subjected, after hydrophilization, to a treatment with a salt solution containing divalent or polyvalent cations in a concentration of not less than 0.02 mol/l, thereby minimizing degradation of the plate and contamination of the printing forms and the development apparatus.

Abstract: An improved method of making lithographic reproductions is disclosed. The method involves several improvements over prior processes, including (a) the combination of random plates and a waterless, dry press for halftone, duotone, tritone and four color separation halftone printing, and (b) the use, in duotone, tritone and four color separation halftone printing of random plates exclusively for all the plates involved in the multi-step printing process.

Abstract: An imaging system (12) for a printing press (10) having an imaging cylinder (44) having an outer surface (46) mobile to movement of charged particles, a device (52) for inducing a charge on the surface of the cylinder (44) of a first polarity, a film (48), a device (50) for passing the film (48) over at least a portion of the outer surface (46) of the imaging cylinder (44), a device (53) for passing charged particles of a second opposite polarity in a pattern through the film (48) onto the outer surface (46) of the imaging cylinder (44), a device (56) for passing a charged particulate material of the second polarity opposite the first polarity onto the film (48) over the pattern information on the cylinder (44) to form an image (80) of the particulate material (58) on the film (48), a device (62) for bonding the particulate material (58) onto the film (48), a print cylinder (36 or 38) having an outer surface (66), and a device (70) for placing a segment of the film (48) over the outer surface (66) of the prin

Abstract: A method of and apparatus for imaging a lithographic plate having a printing surface by exposing the printing surface to plasma jet discharges between the plate and a plasma jet nozzle spaced close to the printing surface of the plate. These plasma jet discharges are sufficient to ablate or otherwise transform one or more layers of the printing surface, thereby changing the affinity of the printing surface for ink and/or water at the points thereof exposed to the discharges so as to produce image spots on the plate.

Abstract: A lithographic printing plate for use on a printing press, with minimal or no additional processing after photoexposure, comprises a printing plate substrate; a photosensitive hydrophilic layer having a polymeric hydrophilic binder and a photopolymerizable, photocrosslinkable or photorearrangeable compound capable of promoting insolubilization or hardening in areas of photoexposure; and a photosensitive hydrophobic layer having a polymeric hydrophobic binder and a photopolymerizable, photocrosslinkable or photorearrangeable compound capable of promoting insolubilization or hardening in areas of photoexposure.

Abstract: A lithographic printing plate that is transformable by spark-discharge techniques so as to change its affinity for ink. The plate features a layered structure including an ink-receptive substrate, a conductive layer and an ink-repellent coating. The ink-repellent coating contains a dispersion of image-support pigments that promote straight-line travel of the spark to the surface of the plate, thereby promoting accurate imaging.

Abstract: Apparatus and method for imaging a lithographic plate having an oleophobic first layer, a metal second layer and an oleophilic third layer. The first and second layers are removed in an imagewise pattern to reveal the third layer, resulting in direct production of image spots. The plate is ready for printing at the conclusion of the imaging process.

Abstract: A method for preparing a printing plate is disclosed. The method comprises contacting a heat sensitive medium, comprising a support and provided thereon a heat transfer layer containing a colorant, a heat fusible substance and a photo-curable composition, with a recording material having a hydrophilic recording surface through the heat transfer layer, applying heat in an image pattern to the contacted materials to transfer the image onto the recording material, and exposing the transferred image to actinic radiation to cure the transferred image.

Abstract: Apparatus and method for imaging a lithographic plate having a metal first layer and a second layer underlying the metal layer, the first and second layers exhibiting different affinities for fountain solution and/or ink. Selective removal of the first layer in an imagewise pattern reveals the second layer, resulting in direct production of image spots. The plate is ready for printing at the conclusion of the imaging process.

Abstract: A developer for a presensitized plate for use in making a lithographic printing plate requiring no dampening water comprises: (1) 1 to 39% by weight of at least one alcohol derivative selected from the group consisting of those represented by the following general formula (I): ##STR1## (wherein R.sup.1 represents an alkyl or alkenyl group having 4 to 12 carbon atoms; R.sup.2 represents a hydrogen atom or a methyl group; and n is an integer ranging from 1 to 6); (2) 1 to 39% by weight of at least one water-soluble organic solvent having a boiling point of not less than 100.degree. C.; and (3) 60 to 98% by weight of water. If this developer is used, foaming is hardly caused during the development processing a PS plate requiring no dampening water, it has excellent developing ability and half tone dot reproduction and can provide an excellent lithographic printing plate free of defects such as scratch marks.

Abstract: A non-film requiring method for applying information to a light sensitive emulsion coated lithographic printing plate comprises obtaining the information applied to a sheet of paper based material, wherein the sheet applied information is essentially opaque to light emanating from a light source and the sheet of paper based material is generally transmissive to the light, positioning the information applied sheet on the printing plate to cover at least a portion of the emulsion, and exposing the sheet covered printing plate to the light thereby directly transferring the information to the printing plate without the necessity of film.

Abstract: To prepare a re-usable lithographic printing plate for printing, an imaging deposit is projected on the plate surface by jet printing using an ejectable substance containing a heat fusible component. The substance forms an imaging deposit which is fused to the surface of the printing plate (1) using a variable frequency and variable power induction heater (5). After printing the imaging, the deposit can be removed from the surface of the printing plate (1) using the same variable frequency induction heater (5) but transferring heat energy at a higher effective energy level to the fusible substance.

Abstract: A printing machine for performing flat-bed printing having a printing form with hydrophobic and hydrophilic area thereon corresponding to an image to be printed, and a device for electrochemically converting, respective areas thereof for producing a printing copy from the hydrophobic into the hydrophilic state by means of a current-conduction arrangement, including a fluid applicator for applying a hydrophobic fluid full-surface to a surface of the printing form, and a control device for controlling the current-conduction arrangement for forming appropriate current paths and for electrochemically removing the hydrophobic fluid area-by-area in accordance with the hydrophilic areas required for the image to be printed; and a method of operation thereof.

Abstract: A method and apparatus are provided for photoelectrochemical reproduction of an image on a plate or roller. For a printing press, the apparatus includes a reusable image roller coated with a oxide semiconductor. A plating solution is applied to the image roller as a thin film. The desired image is written onto the oxide semiconductor by a laser that generates a photoelectrochemical reaction between the semiconductor and the plating solution. In a preferred embodiment, the image roller is coated with hydrophilic p-type NiO. The image is written onto the roller as dots of oleophilic metallic copper, which are formed on the NiO coating by laser-generated cathodic photoelectrodeposition. Subsequent erasure of the metallic copper image can be accomplished by chemical or electrochemical dissolution of the deposited copper. The method functions to create, erase, and recreate high-resolution images directly on a printing press roller without the necessity of precise matrix registration.

Abstract: To program or selectively image or erase a printing form (9) of ferroelectric material, in which the state of polarization of discrete areas of the printing form is controlled, utilizes an electron beam (12) generated by an electron gun (1, 3) which is impinged against a surface area (30) of the ferroelectric printing form. The beam is controlled in accordance with an image to be recorded, for subsequent printing, on the printing form; it is directed to the ferroelectric material by an electron beam focussing and accelerating system, for example similar to the system used in a television camera. The printing form (9) can be sealed with respect to an evacuated electron gun by a slide seal (14, 15) with a vacuum lock, or by a ferrofluidic vacuum lock (18, 20); or the electron gun can be closed by a Lenard window, or an end plate (27) with micro channels or micro ducts (26) therein. The intensity of the beam can be controlled by a suitable image control unit (32a).

Abstract: To provide an electrically controllable printing form, on which the printing image is retained even upon repeated application of printing toner or printing ink formed of toner suspended in a carrier liquid, the printing form (10) has a surface layer (12) of ferroelectric material or, if a gravure form (40), the cells (31) have a bottom (32) of ferroelectric material. The form is programmed under control of a control unit (13, 13') by an electrode (14, 14') which selectively polarizes the ferroelectric material. Upon application of electrically charged toner or ink, the ink or toner particles which are charged oppositely to the polarization of the ferroelectric layer or bottom will be retained, the equally charged particles repelled, so that, by selective positive or negative polarization, two-color printing can be effected at one pass of a printing substrate over the form.

Abstract: A direct-to-press imaging system for use in lithographic printing wherein a master-image printing cylinder is used with separate application of ink and water onto its surface to enable repetitive conveyance of image-formatted ink films onto substrates for printing purposes. The imaging system inlcudes a master-image printing cylinder adapted for receiving a hydrophilic coating layer on its surface and a device for laying down a uniform layer of hydrophilic material on the surface of this cylinder. An apparatus is also provided for applying oleophilic materials in image-formatted patterns on top of the layer of hydrophilic material on the master-image printing cylinder to form a printing structure having separate hydrophilic and oleophilic areas of the format to be printed.

Abstract: A method of reducing printing artifacts in a printing apparatus including a plurality of printing plates, each of which is produced by successive scans of an array of imaging devices wherein the printing artifacts are caused by defective operation of one or more of the imaging devices. Printing artifacts are visually minimized by staggering the imaging devices used to produce separation plates. By staggering the imaging devices, the distance between artifacts can be reduced thereby causing the artifact reproduced in the final composite image to be less accentuated.

Abstract: An apparatus and method for controlling discharge devices used to image a planographic printing plate are disclosed. Imaging information is stored in a first memory while discharge correction data is stored in a second memory. The correction data is used to vary the intervals between imaging discharges to compensate for error between the sensed position of the printing plate with respect to a writing head and the actual position. Printing artifacts are visually minimized by staggering the imaging devices used to produce separation plates.

Abstract: A lithographic printing plate that is transformable by spark-discharge techniques so as to change its affinity for ink. The plate features a layered structure including an ink-receptive substrate, a conductive layer and an ink-repellent coating. The ink-repellent coating contains a dispersion of image-support pigments that promote straight-line travel of the spark to the surface of the plate, thereby promoting accurate imaging.

Abstract: Printing apparatus has at least one print station including a blanket cylinder in rolling contact with an impression cylinder, a print cylinder for supporting a lithographic plate, the plate cylinder being in rolling contact with the blanket cylinder, at least one discharge source for applying an image to a plate supported by the plate cylinder, and a motor for moving the energy source relative to the plate cylinder so that when the plate cylinder is rotated, the discharge source scans a raster on the surface of the plate supported by the plate cylinder. The apparatus may be configured as an in-line or central-impression type press. A controller responsive to picture signals representing an original document repeatedly actuates each discharge source momentarily during the scan thereof so that the discharge source forms on the plate surface an image comprised of dots corresponding to the original document.

Abstract: A method of extending the useful life and/or enhancing the performance of wet or dry lithographic printing plates. A strong curable composition that adheres to the ink-receptive plate areas is first applied to an imaged plate. After removal of the composition from non-image plate areas, it is cured, thereby augmenting the resilience of the ink-receptive plate areas. If imaging of the plate results in surface recesses, the cured composition can enhance plate performance by making the entire surface coplanar.

Abstract: A printing process for producing a print film whose developed image can be transferred to an offset plate or a screen printing screen or even to a cathodically-charged plate, is made by scanning an original and laser writing under the control of the scanning signals on a light-sensitive layer through a diffusion foil. The latent image is then developed and fixed and the resulting film transferred to the printing carrier such as the offset plate or screen printing screen.

Abstract: Apparatus for imaging a lithographic printing plate wherein structure is provided for removing debris generated by an imaging head and adhering to the plate. The debris removing structure may comprise a rotating brush which is selectively movable into and out of contact with the plate as necessary. Cleaning fluid may be delivered to the brush and suction may be used to aid removal of debris loosened by the brush.

Abstract: A direct-to-press imaging system for use in lithographic printing wherein a master-image printing cylinder is used with separate application of ink and water onto its surface to enable repetitive conveyance of image-formatted ink films onto substrates for printing purposes. The imaging system includes a master-image printing cylinder adapted for receiving a hydrophilic coating layer on its surface and a device for laying down a uniform layer of hydrophilic material on the surface of this cylinder. An apparatus is also provided for applying oleophilic material in image-formatted patterns on top of the layer of hydrophilic material on the master-image printing cylinder to form a printing structure having separate hydrophilic and oleophilic areas of the format to be printed.