Design Sensations

Design Sensation
A dye-sublimation printer (or dye-sub printer) is a computer printer which employs a printing process that uses heat to transfer dye onto medium materials such as a plastic card, paper, or fabric. The sublimation name is applied because the dye transitions between the solid and gas states without going through a liquid stage. Many consumer and professional dye-sublimation printers are designed and used for producing photographic prints.
These are not to be confused with dye sublimation heat transfer imprinting printers, which use special inks to create transfers designed to be imprinted on polyester items.
Most dye-sublimation printers use CMYO (Cyan Magenta Yellow Over coating) colors, which differs from the more recognized CMYK colors in that the black dye is eliminated in favor of a clear over coating. This over coating (which has numerous names depending on the manufacturer) is also stored on the ribbon and is effectively a thin laminate which protects the print from discoloration from UV light and the air, while also rendering the print water-resistant.

The dye-sublimation printing process is used to print on polyester or other synthetic fabrics. It is used for applications such as T-shirts, banners, table covers, id cards, sportswear and flags. The original printers were an electrostatic technology using toners but now are generally large format inkjet printers using specially formulated inks. The dye sublimation inks are a pigment suspended in a liquid solvent, like water. The images are initially printed on coated heat-resistant transfer paper as a reverse image of the final design, which is then transferred onto polyester fabric in a heat press operating at a temperature around 180 to 210 C (375 F). Under high temperature and pressure, the dye turns into a gas and permeates the fabric and then solidifies into its fibers. The fabric is permanently dyed so it can be washed without damaging the quality of the image.
Advantages of dye-sublimation over other methods of textile printing:[1]
• Images are permanent and do not peel or fade.
• Dye does not build up on the fabric.
• Colors can be Extraordinarily Brilliant due to the bonding of the dye to the transparent fibers of the synthetic fabric.
• Truly continuous tones can be achieved that are equivalent to photographs, without the use special techniques such as half-screen printing.
• The image can be printed all over the entire item, with no difficulty in printing all the way to the edges.
Disadvantages:
• The printer speed is slow.
• Any creases in the apparel during printing leave blank spots behind.

The most common process lays one color at a time, the dye being stored on a cellophane ribbon that has each color on a separate panel. Each colored panel is the size of the medium that is being printed on; for example, a 6" by 4" dye sub printer would have four 6" by 4" panels.
During the printing cycle, the printer rollers will move the medium and one of the colored panels together under a thermal printing head, which is usually the same width as the shorter dimension of the print medium. Tiny heating elements on the head change temperature rapidly, laying different amounts of dye depending on the amount of heat applied. After being heated into a gas, the dye diffuses onto the printing medium and solidifies.
After the printer finishes covering the medium in one color, it winds the ribbon on to the next color panel and partially ejects the medium from the printer to prepare for the next cycle. The entire process is repeated four times in total: the first three lay the colors onto the medium to form a complete image, while the last one lays the laminate over top. This layer protects the dye from resublimating when handled or exposed to warm conditions.
Print speed
As dye-sublimation printers utilize heat to transfer the dye onto the print media, the printing speed is limited by the speed at which the elements on the thermal head can change temperature. Heating the elements is easy, as a strong electric current can raise the temperature of an element very quickly. However, cooling the elements down, when changing from a darker to a lighter color, is harder and usually involves having a fan/heat sink assembly attached to the print head. The use of multiple heads can also speed up this process, since one head can cool down while the another is printing. Although print times vary among different dye-sublimation printers, a typical cheap home-use dye-sub printer can print a 6" x 4" photo in 45 – 90 seconds. More heavy-duty printers can print much faster; for example, a Shinko CHC-S-2145 dye-sublimation printer can print a 6" x 4" photo in as little as 6.8 seconds. In all cases, the finished print is completely dry once it emerges from the printer.