Hewlett-packard Development Company, L.p.

Barret Kammerzell

Antonio Gracia Verdugo

Joan Albert Jorba Closa

Matthew Allen Shepherd

Scott A White

Marta Coma Vives

Utpal Kumar Sarkar

Sergio Gonzalez

Josep-Maria Serra

Pablo Vidal Alvarez

Daniel Callejo

Guillem Montero Costa

Pablo Vidal ÃLvarez

In an example implementation, a method of compensating for dimensional variation in 3D printing includes receiving a 3D object model that represents a 3D part to be printed. The method also includes receiving a build material type and a position for printing the 3D part within a build volume. The method includes determining from the position, target subvolumes of the build volume into which the 3D part is to be printed, retrieving a dimensional compensation factor associated with each target subvolume, and then applying each dimensional compensation factor to the 3D object model to scale the 3D part according to the position of the 3D part within the build volume.

Compensating for dimensional variation in 3D printing

Herein is disclosed an ink storage unit. The ink storage unit may comprise first and second reservoirs, each having a variable internal volume; a transfer system to transfer ink between the first and second reservoirs such that as ink is transferred from the first reservoir to the second reservoir, the internal volume of the first reservoir decreases and the internal volume of the second reservoir increases.

Ink storage unit having variable volume reservoirs

In an example, a method includes receiving print data indicative of an image to be printed on a substrate. The print data may indicate an image portion in which an image is present and a void portion in which the image is absent. An amount of background print agent to be applied to a region of the substrate corresponding to the locations of the image portion and the void portion on the substrate when the image is printed may be determined. In examples, the amount of background print agent determined to be applied to a region of the substrate corresponding to the location of the void portion on the substrate when the image is printed is greater than the amount of a background print agent to be applied to the region of the substrate corresponding to the location of the image portion on the substrate when the image is printed.

Printing background print agents

A method of printing includes identifying vertical edges in a halftone image. The method also includes determining whether a lightness of color of a first predetermined area to a left side of a respective vertical edge is substantially equal to, less than, or greater than the lightness of color of a second predetermined area to a right side of the respective vertical edge. The method also includes categorizing respective vertical edges left vertical edges, right vertical edges, and neutral vertical edges to prioritize a print direction thereof.

Categorization of vertical edges corresponding to a halftone image

Herein, techniques are described for printing an image on a print media by operation of a printhead to eject a print fluid over the print media. In at least some examples, a printhead temperature parameter is acquired, the parameter being indicative of a temperature at the printhead during printing; alignment of the printhead is corrected based on the printhead temperature parameter; printing is performed on the print media via the printhead according to the corrected alignment.

Printhead alignment correction

In the field of printing technology, non impact printing methods such as inkjet printing may be used to deposit an ink composition onto print media to form an image. An ink composition typically comprises a colorant material and a vehicle, such as an aqueous solution, for delivering the colorant material to the print media. A wide range of such ink compositions is known in the industry. It is also known to use various pre-treatment compositions in combination with ink compositions in order to enhance the quality of a final image. Pre-treatment compositions are often substantially colorless liquid compositions that interact with elements of the ink composition to fix colorant to the print media. Pre-treatment compositions may help to improve image quality for example by reducing image bleeding, edge roughness and other image quality issues.

Spatial misalignment of a pre-treatment composition relative to an ink composition

In one embodiment, a first reference pattern is caused to be printed with transparent ink ejected from a first printhead. A second reference pattern is caused to be printed, with a first colorant ink ejected from a second printhead, to least partially overlap the first reference pattern. The overlapping causes the second reference pattern to be visually discernible where the first and second reference patterns overlap. A background pattern, overlapping and surrounding the first and second reference patterns, is caused to be printed with a second colorant ink less dark than the first colorant ink. The printing of the background pattern causes the first reference pattern to be visually discernible where the first and second reference patterns do not overlap.

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Barcelona, Spain

Barret Kammerzell