Textile printing

Textile printing is the term used to describe printing processes used to print textiles.

Flex and flock foil transfer printing

In flex and flock foil transfer printing, the print motif is cut from special, single-color plastic foils and then transferred to the fabric. In addition to cotton fabrics, polyester, nylon, viscose and blended fabrics can also be printed. The surface of flex films is smooth to matte/soft, while that of flock films is velvety.

Since this printing technique can only print vector graphics without color gradients, it is particularly suitable for printing lettering, pictograms, logos and similar motifs. Multicolor printing is possible (and quite common), but since all work steps have to be performed per color, the costs increase relatively strongly with each additional printing color.

A significant advantage over other textile printing techniques is the high color fastness of the prints, as well as (especially in comparison to screen printing) the rapid and cost-effective possibility of producing individual pieces or small runs. However, since in contrast to screen printing the same amount of work is required for each individual copy (and therefore the cost per piece remains almost constant), this printing technique is less suitable for the production of large runs.

Digiflex printing

In Digiflex printing, a printable flex film is printed using solvent, or eco-solvent ink. As with flex printing, the printed film is cut out using a cutting plotter. Then the motif is applied to a transfer foil and transferred to the textile with a transfer press under pressure and heat. This process is economical even for very small runs and has an extremely high quality compared to conventional transfer foils.

Flock print

Flock printing is a special form of screen printing. Instead of ink, however, a dispersion adhesive is applied here. Flock fibers are then sprinkled into this wet adhesive.

In direct flocking, a special adhesive is applied through the open honeycombs of a screen. The flakes are then shot into the still moist adhesive by means of an electrostat. The charging causes the flocks to arrange themselves vertically and side by side along the electromagnetic field. The finished flock is then dried in the oven. Finally, the flakes that have fallen next to the adhesive surfaces are vacuumed off.

Although this process ensures high wash resistance, at the same time flock printing is limited to single-color motifs, which is why it is often used for back numbers on jerseys, for example.

Screen Printing / Stencil Printing

Screen printing is a printing process in which the printing ink is printed through a fine-mesh fabric onto the material to be printed using a rubber squeegee. At those points of the fabric where no ink is to be printed in accordance with the print image, the mesh openings of the fabric are made impermeable to ink by means of a stencil.

In the screen printing process, it is possible to print on many different materials, both flat (foils, plates, etc.) and shaped (bottles, equipment housings, etc.). Special printing inks are used for this purpose, depending on the material. Mainly paper products, plastics, textiles, ceramics, metal, wood and glass are printed. The print format ranges – depending on the application – from a few centimeters to several meters. One advantage of screen printing is that the ink application can be varied by using different mesh finenesses, so that high ink layer thicknesses can be achieved. Compared to other printing processes, however, the printing speed is relatively low. Screen printing is mainly used in advertising and lettering, textile and ceramic printing, and for industrial applications.

Along with letterpress, gravure and flat (offset) printing, screen printing is also known as through-printing because the printing areas of the screen printing forme are ink-permeable. Historically, screen printing is considered the fourth printing process.

Dye-sublimation printing (Thermal sublimation printing)

A similar process is dye sublimation printing. The difference is that the dyes applied to the carrier film are vaporized by applying heat.

In this process, the dye passes directly from the solid to the gaseous state (sublimation). The gaseous dye penetrates the material to be printed (for paper) or settles on it (for plastic). Depending on the amount of energy supplied to each printing point, the amount of ink to be transferred (up to 64 gradations per color) is also controlled, resulting in high color resolution and brilliant colors. Disadvantages, however, are the slow printing speed, since only one color can be applied at a time during each printing process, and high costs (especially also due to long warm-up times of the device between switching on and the first print readiness compared to other printing processes). In many cases, the printed image must be covered with a transparent protective layer in the final pass to achieve the necessary durability and abrasion resistance. Since the process is used especially for printing digital images, the same printing position must be precisely controlled up to four times per (color) pixel in order to produce the desired color tone with the usual four standard printing colors (cyan, magenta, yellow and black). Because the four colors are available separately from each other and periodically one after the other on the color carrier foil at exactly the same intervals, the carrier foil is usually transported to the subsequent cadre with the next color after a single-color printout of a print line or print area (which thus defines the color offset) and the process is repeated with this until all four colors have been applied.

The print results are of the highest quality and very similar to a conventional color print from a negative. Areas of application in the early days of digital photography were primarily photo studios, but today they are still mainly used for private use because of the excellent print quality combined with compact and inexpensive design, and are increasingly giving way here to the less expensive inkjet technology. Some devices can be connected directly (via Bluetooth or infrared interface) to digital cameras and used as a mobile printing solution on the go.

Transfer film

Here the image is first printed on a carrier film, which is then completely transferred to the fabric with a transfer press. The transfer foil can be printed similar to paper, therefore ordinary PC printers can be used with all colors and screening methods. Accordingly, there are do-it-yourself sets (iron-on foil) for this printing method. However, a transfer press is needed for the transfer, as an ordinary iron does not exert constant pressure, which is necessary. The foil makes the fabric a bit rigid: since it is not as stretchy as the fabric, it gets tears easily, which are noticeable with larger color areas.

Textile direct printing / DTG

“DTG” is the abbreviation for “Direct To Garment”. Using an inkjet printer connected to the PC, special (usually water-based) pigment inks are printed directly onto the textile and then permanently fixed with heat. The print is pleasantly soft to the touch and has good wash resistance, bright colors and high detail fidelity. In contrast to sublimation printing, textiles made of 100% cotton and mixed fabrics (with up to 50% polyester content, depending on the ink) are particularly suitable. Printing on light textile colors is usually unproblematic, since no “underwhite” is required. For dark textiles, a white must be added underneath – similar to screen printing. With most printers currently on the market, this under-white is somewhat problematic, as it requires a lot of maintenance and processing, and the textiles also need to be pre-treated. The advantage of direct textile printing (DTG) is, on the one hand, the flexibility to print textiles individually, e.g. with individual names etc. within a motif, and on the other hand, the high level of detail in photorealistic prints.