With ink jet marking equipment for packaging identification, information is written directly on containers for product identification, date codes and other information that may be difficult to apply with labels.

Factors to consider are:
1. The size of the print.
2. The number of lines of the print.
3. The information printed; i.e. letters or numerals or mix of the two.
4. The material to be printed on.
5. The types and source of ink.

The printers are divided into two broad categories: large print and small print characters. The large print models are for printing on cases. This may be in a single or in multiple lines. Small print models are intended for a much broader range of applications. These go from date codes at the neck or edge of containers to bottles still wet from rinsing. The print heads can be single line to 4 plus lines being printed simultaneously.

Most printer manufacturers offer a line of inks for their units. The most common inks are: water based, alcohol or organic based, pigmented for contrast, UV curable, UV readable, FDA approved, and wet printable.

The substrates or material to be printed on are porous corrugated, cardboard, plastic (PET & PVC), glass, metal, wood and fabric. The choice of the ink in particular will depend on the nature of the substrate.

Another item to consider is the type of information input. Most models have either RS232, USB, or Ethernet input. Some have all these inputs. Some manufacturers offer print heads and controls as separate items. This section deals with complete systems only.