SGIA Digital Equipment Evaluation Methodology
Unbiased Information You Need on Large-Format Digital Inkjet Devices
The purpose of the program is to serve the specialty graphics industry with an objective, central source of information on the subject of large format digital inkjet devices and direct to garment printers. This is achieved by providing consistent digital inkjet equipment information, tested and verified by representatives of SGIA.
Participation by equipment manufacturers is voluntary, but highly encouraged. Evaluations can take place at either a manufacturer showroom, where the equipment can be set up under favorable conditions, or at the facility of a user of the equipment, where a manufacturer representative or experienced operator can use the machine.
An SGIA representative, serving as test observer, conducts timing and measurement. Test images for quality measurements/evaluation, print speed and ink usage are provided by SGIA. Operation of the machine is left to a qualified equipment operator provided/recommended by the equipment manufacturer. Equipment that is not operating as expected will not be tested at that time, and reporting on that unit/model will not take place until the unit is again fully operable.
Description of Machine - A short, narrative description of the machine that includes pertinent specifications (max. print width, resolution, etc.).
Specifications - This section details machine height, width, depth, weight, footprint size, and country of manufacture. Also included in this section are details regarding the firmware version tested, supported OS, and the type of computer interface needed.
Standard or Optional Machine Features - Many digital inkjet devices offer standard or optional features that serve to differentiate a specific piece of equipment from other manufacturers or comparable machines within the same class. Common features may include flatbeds with optional roll-to-roll capabilities, opaque white ink or varnish, or materials handling (take on/take off) capabilities. This section lists standard or optional features and if applicable, their list price.
Print Width and Dimensions - Details are provided for a number of criteria, including maximum print width and length, maximum roll width, maximum rigid media size and maximum rigid media print size, as well as maximum media thickness. For direct to garment inkjet devices, the maximum platen adjustment range and the adjustment method, (manual or automatic) are also provided.
Power and Venting Requirements - This section specifies the electrical requirement, compressed air requirement, and venting configuration of the device. When available from the manufacturer we will report the estimated kWh for an 8 hour workday.
Number of Colors - This section provides colors that are supported by the device (CMYK, CMYKW, Varnish, etc.).
Printing Resolutions - This section of the report describes the printing modes supported which are listed as either the actual resolution (720x720, 1440x1440, etc.) or by name (high production, production, high quality). This will also include the maximum printing resolution for the device.
Activities for Standard Routine Maintenance - A list of standard routine maintenance activities that the manufacturer recommends should be performed on the device on a regular basis (daily, weekly, monthly, and annually). Approximate time to complete each activity and recommended frequency are included. Examples include time to complete a head purge, ink change, head alignment and cleaning/capping station maintenance.
Service/Warranty Package - A description of the machine's warranty package is included in this section.
Description of Training & Service Structure - The training and service structure used to help support and maintain the digital device is described here, along with the price of the service if applicable. Also, the organization of the service structure is briefly described, in order to present a view of the complexity and capability of the Manufacturer’s support network.
RIP Availability/Compatibility - This section includes a listing of RIP software packages that support the device, as well as the cost (where possible) for the software packages.
UV Lamp Information - For wide format output devices using ultraviolet curing systems, this section provides a description of the machine's curing system and information on adjusting and controlling the system. If LED lamps are used, that information will be included here. Included in this section is the expected life span of these lamps and replacement cost if available.
Ink - This section includes the type of ink delivery system (bulk, cartridge), the onboard ink volume, and whether 3rd party inks are available and/or will void the warranty. Ink cost is also reported for OEM ink, or that which is recommended for the unit by the Manufacturer. Ink costs are listed as cost per unit sold (liters, 500ml, 250ml, etc.). Ink costs are based on list price of inks as provided by the manufacturer.
Manufacturer's Suggested Retail Price - The suggested retail price of the machine is listed here. Purchase prices are often subject to negotiation, and may be adjusted by the Manufacturer or the Distributor.
Print Heads - This section lists the print head Manufacturer and model number, the number of heads installed on the device, the number of print heads per color, the number of nozzles per print head, the droplet size or range, the life expectancy of the print head, and the cost of replacement print heads.
Environment, Safety, and Health - This section includes recommended operating temperature and humidity ranges, and those issues associated with a safe workplace such as possible exposure to UV light and/or exposed moving parts.
Company Contact - Contact information, including mailing address, email, phone number, and Web site of the Manufacturer.
Testing by SGIA
Color Gamut and Density- A color test chart is printed using a standardized X-Rite color target (IT8.7/4). The chart is run first with no ICC profile information (color management turned off). On the second run, the settings are determined by the manufacturer’s operator and those settings are reported. The L*A*B* values of the paper/media used is also reported. The printed target is then scanned using the X-rite i1 Pro and i1 Profiler software to build a model of the device's color gamut. A visual model of the machine's inherent color gamut is presented from both prints, along with comparisons to Adobe RGB and GRACol2006 Coated1v2 color spaces.
For density readings, an initial ink limit chart (CMYK from 0-100% ink, usually the first ink limiting chart in most RIP software) is run with no color management and no ink limiting turned on. The goal is to report the overall density that the printer is capable of achieving at different production settings. The settings for each reading and the density achieved are reported.
Print Speeds for Bi-Directional Printing - Print times are recorded for a standardized print image, sized to maximum print width, in three different modes offered by the device (e.g. high speed, production, high quality). For those direct to garment devices capable of printing dark shirts with white ink, the identical test is repeated to provide print times for dark garments. Time measurements begin when the print head begins printing and ends when the print is complete. This measurement does not include RIP time. Results are outlined in a table showing the image size, resolution, and square meters or feet per hour.
4’x8’ Boards per Hour - This section is used specifically for flatbed and hybrid equipment evaluations and reports the number of boards per hour using 4’x8’ sheets using a standard test image.
Print Quality – An SGIA test image is printed to evaluate color and gray balance. The image includes various industry standard wedges along with Pantone spot colors set up as both spot and CMYK. The output rendering intent for this print is set to Colorimetric with BPC. The Pantone spot colors are measured and the Delta E is reported. Neutral gray is also evaluated on this test image. A square of gray was created by mixing 50% cyan, 40% magenta, and 40% yellow. Density readings of CMY are read with the X-rite Exact and the results are reported.
The SGIA test image is also made up of a number of print images to evaluate facial tones, print detail, and overall tonal range. A control image is used to compare these print images. Print registration will be demonstrated by evaluating 6, 12, and 18 pt. type printed “black on white” and then reversed out of three different color blocks at the highest resolution available along with a CMYK registration mark – these images will be displayed with a 10x digital microscope.
Print Repeatability and Uniformity – A Tucanna “Quick Check” control wedge is printed so that it takes into account the maximum width of the print area. Measurements from the far right, center, and far left are taken to compute DE across the width of the print area.
Ink usage – When the SGIA test image is printed the ink usage or consumption is reported via the RIP or the printer controller. Ink usage will be noted as the total volume used to print the sample image. Any maintenance cleanings where ink is purged will be noted when applicable and the approximate amount of ink used for these activities will also be noted.
UV Adhesion Test – This is the typical test for adhesion adopted by inkjet manufacturers. The Cross Hatch Test (CHT) is according to standard EN ISO 2409/DIN 53151/ASTM D 3002, ASTM D 3359. Basically this test cuts a tight grid into the ink film using a standard tool (e.g. Elcometer 107/1540/1542). After cutting the grid, you then use a standard tape, which is adhered to the grid and removed in a prescribed manner. Depending on how much ink stays on the media, the test result range is between 0 (low adhesion) up to 5 (high adhesion). Most people testing with this method use the 1mm spacing. The test is performed after allowing the print to cure for more than 24 hours.
White Ink Opacity – For those printers offering white as an option, we ask the expert operator to print white ink (at least a 2” square) on both a white substrate and a black substrate. The L-value of the two substrates will be measured and reported. We then measure the L-value of the white ink from both substrates and report those values. The difference in L-value will be an estimation of the opacity of the white ink.
SGIA Digital Equipment Evaluation Methodology, Rev. Dec. 2014