Omnijet Media Faq’s

Linearisation is a calibration process that helps to counteract variability. This makes output on a device consistent, and repeatable. The reproduction curve is modified during a linearisation process to bring the output results back to a known point.

The exact procedure you use to linearise your device will depend on the RIP or printer driver you are using. In general, a target file generated by the RIP/output software is printed. The resulting print will have step wedge ramps from each of the output devices primary colours. The patches on the print are read into the computer using a measuring device like a spectrophotometer, densitometer, or colourimeter. The quality of the measuring device has a big impact on the accuracy of the readings used for the linearisation. Once the readings are in the software, a mathematical correction is made to the reproduction curve of the device. These corrections should bring the printer back to a known state.

To correct color shifts and ink loads caused by environmental factors like temperature and humidity.

On a properly maintained printer you should linearise after cleaning, or changing the cartridges, changing the media, or changing the print settings.

There are a lot of factors that can cause premature failure of an ink cartridge. This will depend on the technology of the printer, Piezo, thermal, etc. and elements that impact its life. Some of these elements include, abrasion, temperature, voltage, humidity, pH of the inks, viscosity of the inks, and drying characteristics of the inks, dust and contamination. Ink can also dry in the jets of the print head causing a blocked jet. This will normally happen if the printer is not used for long periods of time. It is suggested that you run a small print or prime the printer at least several times a day to avoid this problem.

Banding can come in many forms, horizontal (direction of print head), vertical (direction of paper travel), micro, etc. In general, bands are a result of the printing mechanics failing to place the ink on the paper evenly. The type of bands you are seeing will give you clues as to what part of the mechanical printing process is breaking down. Horizontal banding can indicate a print head alignment problem. To cure this run the print head alignment procedure as indicated in the printer manual. Vertical banding may be caused by an environmental condition. If the humidity is low the media may cockle during printing, this can cause the media to be closer to the print head where there is a high ink load. This will result in low density banding. To correct this, the humidity needs to be raised so that it falls within the media manufacture’s specifications.

An ICC profile is a file that describes how a scanner, monitor or printer reproduces colour. These profiles are called “Device specific”.

ICC stands for International Colour Consortium.

You need a profile in order to use ICC colour management. When a custom ICC colour profile is properly implemented ICC colour management will provide the best possible reproduction when trying to match the original.

A custom profile is a profile created on your device. The custom profile will take into account the ink, media, printer and RIP you use to generate the profile.

A generic ICC profile describes a colour space that is not specific to any one particular device. A generic ICC profile can be used in place of a custom ICC profile when a custom ICC profile is not available. The results are never as accurate as what can be achieved when a custom ICC profile is used.

Thermal ink jet printers use water based inks that are pumped through a disposable jetting system (a cartridge) by boiling the ink above a specific nozzle onto coated substrates. Printers using Piezo technology have a permanent jetting system that uses vibrating crystals to pump a variety of liquids, such as water, oil or solvent based inks, onto coated and un-coated substrates.

All three liquids act as a carrier of a dye or pigment onto a given substrate. The jetting system regulates the types of inks that can be used, e.g. Thermal Ink Jet- water-based only, Piezo Ink Jet- water, oil, solvent, etc.. Specific substrates are required for different inks as well; Coated- water & oil, Un-coated- solvent.

Dye-based inks are usually used for indoor graphics. They incorporate soluble organic colourants that produce outstanding colour saturation but are not generally waterproof and can fade quickly in direct sunlight. Pigment-based inks use insoluble colourants that can be used for outdoor as well as indoor graphics. They are highly resistant to fading but, depending on the brand of inks used, may offer slightly muted colours. Pigment-based inks are highly water resistant and may last indoors, for many generations.