The G7 process is well known throughout the graphic arts industry and there are more than 800 print companies certified to be in compliance with the G7 process.
The G7 process is based on grey-balance control of the four-color printing process. This grey-balance is achieved through the Neutral print density curve (NPDC), which is used for determining the correct amount of cyan, magenta and yellow to achieve a neutral three-color grey depending on the printed ink density for black. The evaluation of achieving this grey balance can be done through the measurement of the P2P25X test target. This test target contains gradation scales for the four process colors and also for three-color grey.
G7 can be used for sheetfed printing, flexography and screen printing. The question that comes to mind is the following: Can the G7 process not only be applied to professional proofing systems, but also to small office/home office printers?
There is a vast number of home/small office printers on the market and many documents get printed in color, but the outcome is quite different from printer to printer. This study is aiming to see if it is possible to determine the feasibility to apply the G7 process to the small office/home office print market. Some of these printers are using 4 or more colors for printing any document. This could influence also the capabilities of the printer to be able to conform to the G7 process.
Some printers come with predefined pre-sets in regards to printing on different kinds of papers from plain office type paper to photo paper. It will be determined how close these predefined pre-sets are in regards to a neutral grey balance.
Besides using small office/home office inkjet printers the study will also include toner-based printing systems. These can include desktop laser printers and professional toner-based printers.
The evaluation will mainly be done with the P2P25X target and the Curve3 software.
It is the goal of this study to include devices that are aimed at the consumer, prosumer and professional market for inkjet and toner-based printing devices.
The big difference between consumer, prosumer and professional print devices is the way that the color and print information is transferred from the computer to the output device. Most likely the consumer and prosumer devices will be addressed as RGB devices, although the colors that are used for printing are CMYK. Professional device quite often have a software-based RIP system as digital front end, which addressed the device as a CMYK device. It will be interesting to see if it is possible to apply the G7 method to print devices that are addressed as RBG devices.
The study will take a snapshot at the current state of these devices in regards to the applicability of the G7 process and also to see if there might be a simpler way to improve the print consistency between small office/home office printers on similar types of paper.
The consumer device used in this study and the two professional print devices were able to achieve G7 conformance.