T shirt printing has come a long way from simple silk screening. Aside from screen printing other methods include direct-to-garment printing and thermal transfer. Each of these methods has a different effect and can produce either vibrant or dull colors.

The intricacy of design is also dependent on the t shirt printing method to use. One method may only produce six-color designs while another can print a thousand colors on the fabric. Understanding each method can help you decide which method to use for t shirt printing.

Screen printing makes use of a mesh or screen made of polymer, a squeegee made of rubber, and a t-shirt printing machine. The mesh used to be made of silk because the screen printing method originated in China. However, because of silk’s expensiveness, manufacturers have started creating fine screens from polymer instead.

These modern screen printing meshes were as durable as the silk screens of yore. When they are damaged, these polymer meshes will not be as costly to dispose of as when they are made of silk. Polymer is also easier to gather as a resource material compared to silk, which is hard to come by.

The screen printing process involves the following steps:
The client discusses with the t shirt printing company the requirements of the design. These will include the number of colors to use, the final effect the client wants for the design, the color and type of the fabric, the number of t shirts to produce, and the t shirt printing methods to use.
The t shirt printing company then prepares the ink, the rotary printing machine, the screen printing meshes, and the soft copy of the design, which has to be edited using an imaging software such as Photoshop, and then printed from the computer to the acetate.

The design has to be printed in its negative image, which means the areas where the ink should fill up must be the ones that are opaque. The areas that do not need any ink should be transparent. The reason for a negative image is for the creation of the stenciled image on the mesh.
Using an emulsion, the stencil is created by placing the acetate with the printed design on top of the mesh, and then exposing the two to UV light. The UV light will harden the exposed areas with emulsion underneath the acetate, while the emulsion in those opaque areas will remain soft and washable with water. After washing away the soft emulsion, the hardened emulsion will form the stenciled image.

With your mesh ready with the stenciled image, the t-shirt printing process now begins. The t shirts are laid on the platform in the t-shirt printing machine. The back of the shirt should be protected from leakage. The mesh for each color should be tightly screwed so it will not move and smudge the design.
Each color of the ink is applied to the screen depending on the area they are needed. The stenciled image for each color will also differ to match the area where the color is needed. The angle of the squeegee and the pressure applied will determine the depth and consistency of the color.

As each custom printed t-shirt is finished, they are immediately "cured," which is a process of embedding the ink into the fabric by exposing it to intense heat. A special heater is used for certain types of inks, especially the water-based types.

Direct-to-Garment Printing (DTG) Method of T shirt Printing

Direct-to-garment printing uses a modified inkjet printer to directly print the design on the t-shirt without the use of a stenciled image or a squeegee to apply ink through a mesh. The textile ink is the same one used in screen printing the t shirt.

Because of the reduction of the steps in the t-shirt printing process, the DTG method increases the turnaround time. More shirts can be printed on in less time. Aside from that, because DTG does not use a mesh for printing, the number of colors and the intricacy of design is more flexible and customizable.

T Shirt Printing Using Thermal Transfer

The thermal transfer method uses the same modified inkjet printer to print the textile ink onto a special paper that reacts to heat. When heat and pressure are applied to this special paper, the design is transferred to the fabric. Sometimes, water is applied first to the back of the paper before being ironed over the t-shirt. Other times, the back of the paper is directly ironed over after being placed on top of the fabric.

These are the major processes used in t-shirt printing. There may be other methods such as flex and flock printing, but these three methods are the most used by t shirt printing companies. They are also the most cost-efficient and most requested by clients. The other t-shirt printing methods are used in combination to produce custom printed t-shirt designs.