T-Shirt Printing: Techniques And Processes For Custom Designs

T-shirt printing is an involved process that allows you to design your own T-shirts. There are several methods for printing designs on T-shirts, each with its own pros and cons. The most popular methods include screen printing, direct-to-garment (DTG) printing, heat transfer printing, and embroidery. Screen printing is the most traditional method, where ink is applied to a T-shirt using a mesh screen stencil. It is versatile, effective, and produces vibrant, durable designs but requires a new screen for each colour or design revision. DTG printing is a newer method that uses an inkjet printer to print designs directly onto the T-shirt, making it ideal for complex designs but less viable for large orders. Heat transfer printing uses a heat press to transfer a design onto a T-shirt and is suitable for all-over prints. Embroidery is another option that produces durable and sophisticated-looking designs but has limited colour variations and a smaller print area. Other methods include dye sublimation, direct-to-film (DTF) printing, plastisol transfers, and CAD heat transfer vinyl printing.

Screen printing

Step 1: Create Your Artwork

Firstly, you need to have something to print on the shirt. You can design the artwork yourself or have a customer bring it to you. The quality of the artwork will determine the quality of the screen print, so it is important to start with a good design. If you are printing in multiple colours, you will need to separate the colours and create different screens for each colour in your design.

Step 2: Prepare Your Screen

A screen printing frame consists of a wood or aluminium frame stretched with polyester mesh. You will need to coat the mesh with emulsion and expose the design onto the screen. Before coating the mesh, it needs to be cleaned with a special screen printing degreaser to ensure any dust, lint, or particles are removed. Emulsion is light-sensitive, so this step should be done in a darkroom with special light-safe yellow bulbs.

Step 3: Expose the Image

Once the screen is coated and dried, you need to expose the image onto the screen. Place a film positive of your artwork onto the screen and expose it with a screen printing exposure unit or an exposure lightbulb for a set amount of time. The emulsion will harden where it is exposed to light, and the area covered by the film positive will remain soft. After exposing the screen, simply rinse it with water, and the soft part of the emulsion will wash away, leaving the mesh open in the shape of your design.

Step 4: Set Up the Screen Printing Press

Before you start printing, you need to set up the screens on a screen printing press. A screen printing press consists of a base that holds printing platens and a number of colour arms. The number of colour arms will determine how many colours you can print at one time.

Step 5: Prepare the T-Shirt

Before loading the t-shirt onto the platen, apply pallet adhesive to the platen to ensure the shirt stays in place. Load your shirt onto the press and get your printhead aligned. Before locking the printhead into place, flood the screen with ink.

Step 6: Print Your Design

Once the printhead is locked down, push or pull the screen printing ink across the screen to deposit the ink onto the shirt. You may need to do this more than once, depending on how much ink is deposited. If you are printing multiple colours, repeat this step with your other screens.

Step 7: Cure the Ink

After you have finished printing, you need to cure the ink. Curing is when the ink dries and sets into the garment. You can cure a shirt with a conveyor dryer or a flash dryer. The temperature required to cure the ink will vary, so be sure to read the instructions on the ink container. If a shirt is not cured properly, the ink will not last, and the print will degrade over time.

Pros and Cons of Screen Printing

Direct-to-garment (DTG) printing

The Process

The DTG printing process involves several steps to ensure the best results:

• Pre-treatment: This step is crucial as it helps the ink adhere better to the fabric, prevents ink from washing off, and enhances colour vibrancy. Pre-treatment can be applied by hand-spraying or using a pre-treatment machine.
• White underbase: All garments, except white ones, have a white underbase applied first to improve the final print's vibrancy.
• Printing: Once the underbase is printed, the DTG printer adds the remaining colours, just like an inkjet printer, using a mix of cyan, magenta, yellow, and black inks.
• Drying and curing: After printing, the garment needs to dry and cure to ensure the ink resists washing and doesn't dull over time. This can be done using a conveyor dryer (common for industrial manufacturers) or a heat press for smaller businesses.

Pros and Cons

DTG printing has several advantages and disadvantages to consider:

Pros:

• High-detail image quality and unlimited colours: DTG printing can reproduce intricate designs with a full spectrum of colours, resulting in detailed and high-quality prints.
• No minimum order quantity: With no minimum order requirements, DTG printing is perfect for printing small batches or testing new designs.
• Environmentally friendly: DTG printing uses water-based, non-toxic, and vegan inks, making it a more sustainable choice.
• Versatility on fabrics: While DTG works best on natural fabrics like cotton, technological advancements have expanded its compatibility with other materials.

Cons:

• Limited textile compatibility: DTG printing works best on textiles containing at least 50% cotton to enhance absorption and improve print quality.
• Limited application surfaces: DTG print surfaces are typically smaller than those possible with other methods, such as sublimation printing, which allows for all-over prints.
• Not optimal for bulk orders: DTG printing is slower than other methods and is, therefore, more suitable for small orders or print-on-demand businesses.

Best Fabrics for DTG Printing

To achieve the best results, it's recommended to use natural fabrics that absorb ink well, such as:

• Combed and ring-spun cotton
• Linen and other natural textiles

DTG printing is an excellent choice for those seeking to add complex, multi-colour designs to various garments, including t-shirts, hoodies, tote bags, and more. It offers high-quality, vibrant prints that are comfortable and durable.

Heat transfer printing

Step 1: Creating a Design

Use graphic design software to create your desired design on a computer. This can include text, images, or a combination of both. Ensure that your design is in a vector format, such as AI, PDF, or EPS, as this will be required when submitting your design for printing.

Step 2: Printing the Design

Print your design onto heat transfer paper using inkjet, sublimation, screen print, or pigment ink. This paper is specially designed to transfer the printed design onto a t-shirt when heat and pressure are applied.

Step 3: Trimming the Image (If Necessary)

If needed, use a vinyl cutter to trim the edges of the printed image. Any part of the design that is not cut away will appear on the final product.

Step 4: Warming Up the Heat Press

Set the temperature of the heat press machine between 340°F to 365°F (171°C to 185°C). The exact temperature and pressure settings may vary depending on the type of fabric you are using, so it is important to refer to the instructions provided by your transfer supplier.

Step 5: Adjusting the Pressure

Adjust the pressure on the heat press according to the thickness of the fabric. As a general rule, use lighter pressure for thicker materials and higher pressure for thinner fabrics.

Step 6: Setting the Time

Different heat transfer methods require different press durations. Here are some common methods and their corresponding press times:

• Vinyl Transfer: 7-15 seconds
• Digital Transfer: 10-20 seconds
• Dye Sublimation Transfer: 25-30 seconds

Step 7: Positioning the T-shirt and Transfer Paper

Place the t-shirt onto the platen of the heat press machine. Position the heat transfer paper, design side down, on the desired location of the t-shirt.

Step 8: Pressing the Product

Close the heat press by pulling down the handle. This initiates the transfer process, applying heat and pressure to imprint the design onto the t-shirt.

Step 9: Removing the Film

Once the timer goes off, open the heat press and carefully remove the film. Your custom-printed t-shirt is now ready!

Heat Transfer Methods:

There are two main heat transfer methods: Vinyl Heat Transfer and Digital Heat Transfer.

Vinyl Heat Transfer:

Vinyl heat transfer, or heat transfer vinyl (HTV), is a thin sheet of polyurethane with a heat-activated adhesive backing. When the right temperature and pressure are applied, the vinyl easily transfers to the t-shirt, resulting in a durable and long-lasting print.

Digital Heat Transfer:

Digital heat transfer is similar to printing a photograph onto a garment. It uses regular transfer paper instead of vinyl transfer paper. When heat and pressure are applied, the ink adheres to the garment, transferring the graphic image.

Pros and Cons of Heat Transfer Printing:

Pros:

• Environmentally friendly and minimizes carbon footprint.
• Produces high-resolution, high-quality products.
• Cost-effective for small orders due to a short setup process.
• Can utilize multiple colours.

Cons:

• May not last as long as traditional screen printing due to washing and drying.
• Gives the design a rubbery feel due to printer ink coverage.
• Unsuitable for large quantity orders as it is time-consuming and expensive.

Dye-sublimation printing

The unique aspect of dye-sublimation printing is that the gas integrates with the polyester fabric, becoming a part of the material rather than just sitting on the surface. This results in exceptionally vibrant colours and durable prints that will not fade, crack, peel, or deteriorate. The ink is seamlessly incorporated into the fabric, making the print soft to the touch and breathable.

However, dye-sublimation printing is only compatible with polyblend-based t-shirts, with higher polyester content resulting in more vibrant colours. Folds and creases, such as those under the sleeves, may remain undyed. Additionally, this printing method is not the most affordable option.

Overall, dye-sublimation printing is an excellent choice for those seeking long-lasting, high-quality prints with the added benefit of an all-over print effect that other methods like screen printing and DTG printing cannot achieve.

Direct-to-film (DTF) printing

The DTF printing process involves printing a design onto a piece of PET film (a special film with a coating that helps transfer designs) and then transferring it to the fabric using a heat press machine. This method offers a simple and cost-effective alternative to other printing techniques, as it doesn't require any pretreatment of the fabric and can work on both dark and light colours.

Step 1: Preparing the Film

First, a PET film is placed in the DTF printing machine, where the entire design is printed in colour. Then, the machine prints a white layer over the entire image, covering the first layer. After that, an adhesive powder is uniformly applied onto the wet ink, and the film is heated to prepare it for fabric transfer.

Step 2: Pre-pressing Fabric and Using a Heat Press

The fabric receiving the design is kept under a heat press to dehumidify and pre-flatten it. Then, the printed film is placed on the pre-pressed fabric, and the design is transferred using the heat press for 15 to 20 seconds at an average temperature of 165°C.

Step 3: Peeling the Film and Post-pressing the Fabric

Once the design has been transferred, the film is carefully hot-peeled, and the fabric is flattened a second time in the heat press to improve the design's durability. After post-pressing, the garment is ready to be packed and shipped to customers.

DTF printing offers several advantages over other printing methods. It is quick and easy to do, making it a great choice for printing detailed designs on bulky, outdoor apparel. It also allows for printing on a wide range of fabrics, including cotton, polyester, and their blends, as well as tougher fabrics like nylon and fleece. Additionally, DTF printing does not require any pretreatment of the fabric, making it more cost-effective than other methods.

However, there are also some disadvantages to consider. The printed area is slightly more noticeable than subliminal printing, and the colour vibrancy may be lower. Additionally, DTF printing is not ideal for large designs as it can be less breathable, leading to discomfort during extended wear or physical activity.

Frequently asked questions