Manufacturer's technical level: this is very important, some manufacturers can do six color equipment, some manufacturers can do eight color equipment, and some manufacturers can do nine color equipment.
Process requirements: mainly refers to whether the printing pattern needs embossing effect, if needed, you need head to print white ink. Whether need to print the varnish? And if necessary, add more print head.
Print head characteristics: characteristic of different print head is different , some can print eight colors with one head(EPSON five generation print head), some one head one color (Toshiba nozzle), some spray two colors with a head(Ricoh Gen5),
Color requirements: in addition to the basic four colors, there are six colors, eight colors, nine colors, and eleven colors, then the corresponding number of print head is quite different.