What is heat transfer printing?
Thermal transfer printing is one of three branches of thermal printing technology including: thermal transfer, dye sublimation and thermal wax transfer. Heat transfer printing technology was first invented by SATO Corporation (Japan) with the world’s first heat transfer printer, SATO M – 2311) launched in 1981.
This is a digital printing method applied to paper and other printed materials by using heat to heat the ribbon coating so that it adheres to the surface of the printed material. This technology includes two main stages: printing designs on heat transfer paper and heat pressing to transfer those prints to the material to be printed.
Compared to other printing methods, heat transfer printing is the most commonly used method and we also use this method at our Dallas T-shirt Printing Store. Because they have the ability to create beautiful, sharp images in a short time and at a low cost.
Principles of professional t-shirt printing
The operating principle of the heat transfer t-shirt printer is: the laser automatic color mixing printer prints on a specialized film sheet. Then put the paper on the surface of that textile. You can use a press and heat to transfer the ink to the surface of the fabric. From there, the name heat transfer printing was born.
HEAT TRANSFER PRINTING WITHOUT LIMITS ON PRINTING COLORS
Unlike silk fabric, the more colors used, the higher the cost. However, with thermal transfer printing, each printed image is printed using an automatic color-mixing laser inkjet printer. Therefore, you can print images with very high sharpness and show full effects, including landscape or 3D images.
The cost of heat transfer printing depends only on the printed area, number of printing positions and background color of the printed fabric.
Advantages of heat transfer printing technology on t-shirts
- Prints are diverse, from photos to 3D images.
- High quality printing, sharp, realistic and durable.
- Prints are not affected by cleaning chemicals.
- The ink penetrates the fabric. The print does not cause stiffness or clumping of the shirt, and the smooth surface does not cause discomfort to the wearer.
- Large, full-length prints can be printed.
- Can be made in large quantities and at low cost.
- Production time is faster than other printing types.
Disadvantages of heat transfer printing technology on shirts
- Heat transfer printing on black, dark fabric is difficult. The ink in this method usually prints well on light-colored fabric surfaces. With dark fabrics, the durability of the print will be less, and the sharpness and sophistication will also decrease.
- Printing on 100% cotton fabric is also a difficulty with this method. The colors on cotton fabric are often lighter than the design. And the durability is not as good as poly fabric.
Some types of heat transfer t-shirt printing
- Heat transfer printing on white poly shirts: This is the easiest printing technique, low cost and high quality. Prints are sharp, delicate, true to color and highly durable.
- Heat transfer printing on cotton shirts : The technique of printing on cotton fabric is more complicated than printing on poly fabric. First of all, we will use a chemical as a transparent lining. After the printing process, the ink and chemical layer will adhere firmly to the fabric surface, and provide better print quality than conventional printing techniques.
- Printing on decal: this is a technique for printing in large quantities. This shirt printing method applies the print to decal sheets and then sticks them to the surface of the shirt. The size of this print is usually small, commonly applied to men’s shirts and sports team t-shirts.
- Printing on film: This technique uses film that is a high-quality, transparent material with special ink applied. In addition to fabric substrates, this type of ink also allows printing on other materials such as porcelain, glass, shoes, etc. When heat transfer printing on dark fabric substrates, this is also the technique of choice, because it overcomes the disadvantages inherent point of heat transfer printing, although the price is not cheap at all.
Necessary equipment for heat transfer t-shirt printing
5.1. Thermal transfer printer
This is definitely an indispensable device. Thermal transfer printers are designed like regular printers but are installed with a thermal transfer ink system. Depending on the scale and size of printed materials, we have different types of printers:
- A4 size printer: Epson T50 printer, Epson T60 printer, Epson R230x printer, …
- A3 size printer: Epson 1390 printer, Epson 1400 printer, …
5.2. Heat Press Machine
Depending on each product, we have different types of heat press machines. For T-shirts or ceramic tiles, crystal, wood, etc., people usually use a flat heat press machine. For disc rims, natural stones, metals, phone cases, etc., people use 3D vacuum heat presses. In addition, multi-purpose heat presses are also used quite a lot, because they can heat transfer print on most materials.
5.3. Heat transfer printing paper
This type of paper is designed specifically for heat transfer printing technology. They are used to print photos on shirts. At the same time, after the heat pressing process, they must also easily separate the image to allow the print to adhere to the surface of the shirt.
5.4. Thermal tape and cutting machine
These are devices that cut heat transfer paper and fix them on the surface of t-shirts or other materials to be printed.
Heat transfer printing on black t-shirts
As mentioned above, the disadvantage of sublimation t-shirt printing is that it is difficult to do on black fabric. Difficult but not impossible. However, the cost of heat transfer printing technology on black T-shirts is very high, and is often not applied, except for the need for individual or group printed shirts. There are 3 ways to heat transfer print on black t-shirts:
- 2-skin heat transfer printing: In this printing technique, the background color of the fabric is printed directly with heat transfer printing on the entire shirt. When printed, the fabric will have white on the inside and the outside color or pattern as designed. This type of printing requires an A0 size printer, the image overflows and is extremely ink-consuming. Therefore, it can be said that this type of heat transfer printing on dark shirts has the highest cost.
- Using specialized ink and lining: Technicians will treat the dark fabric surface with a specialized chemical. This chemical layer forms a transparent lining. Under the influence of heat, this lining and the printing ink will adhere firmly to the fabric, creating the most realistic print.
- Using high-quality film: This technique is not only used when printing on dark fabrics, but also prints in many styles such as glitter, glitter, and thick images. These films are often used in the footwear industry.
The quality of printing on black t-shirts when using high-quality film is much higher than with conventional heat transfer printing techniques.
Price for heat transfer t-shirt printing
Unlike screen printing where the cost is determined by the number of printed colors, the cost of heat transfer printing depends on the print size, fabric color and printing location.
- The larger the image, the higher the cost will be due to the use of more ink. Especially when printing the entire shirt surface.
- The darker the background of the shirt, the higher the printing cost. Because heat transfer printing only prints well on light-colored fabrics. With dark backgrounds, other techniques need to be applied to produce beautiful and quality images.
- Printing location is also a factor that determines the cost of heat transfer printing. Printing on the back or chest is cheaper than other difficult locations such as sleeves or collars.