Screen Printing for T Shirts & Clothing

Screen printing is one of the most economical options for large t shirt printing orders, with some machines able to print 600 shirts an hour. This means they can be much cheaper to produce compared with other customisation methods, such as embroidery.

The option of screen printing also gives a great, high quality finish, especially for dark inks on light garments. Some high end digital machines are catching up to this quality, however, the look and feel of a well produced screen print is still superior.

What is Screen Printing?

Screen printing is one of the printing methods we use to create custom designs, patterns and logos on clothing. Screen printing, put simply, consists of ink being spread over a screen with the chosen design placed in between.
Screen printing is a popular printing method for personalised t shirts, hoodies, and many other garment types, and can be seen in abundance on the high street. This is largely due to the finish of the print, with excellent quality and a long lasting design.

Screen printing should not be confused with heat transfer printing, which can produce lesser quality prints which are not always as long lasting.

Should I Use Screen Printing?

Why screen printing? Well, it is one of the most popular forms of printing when creating custom clothing. This technique is the recommended method of printing when producing a large quantity of garments with the same design. This is due to the ink or design not needing to be changed after every print, which is the case when creating multiple designs or different colours.

Screen printing is an art form all of its own and our talented team put all their effort into achieving the best possible outcome. This includes making sure the print doesn’t crack, colours don’t overlap and ensuring that the ink is thick enough. All of this combined ensures our customers receive a high quality product, with high attention to detail. 

 The Process - How Does Screen Printing Work?

If you are unsure of the particular method of customisation that would be best suited to your brand or project, this guide will hopefully tell you everything you need to know about the screen printing process to help you make an informed decision.

The Screen

The screen printing process begins with a screen. The screen is made up of 2 parts, usually an aluminium frame (which comes in various sizes) and a mesh. The mesh is glued to the frame to create a ‘drum tight’ object, allowing reduced movement when passing the ink through to create the design.

The mesh is a variable which can be changed depending on the print objective, offering a choice of a heavy or light ink deposit. Choosing a coarser mesh allows more ink to pass through, whereas a finer mesh allows less ink to pass through resulting in a precise result. When printing a more detailed design, a finer mesh is required.

Due to the mesh being fixed and stretched tightly to the frame, the tension relaxes over time, meaning the mesh needs to be replaced regularly to ensure that the best possible outcome is achieved every time.

What Makes a Good Screen

Our Shirtworks mantra is ‘good printing starts with good screens’. Every good tradesperson knows that they are only as good as the tools they are working with, and this is very much the case when it comes to screen printing. Substandard screens will result in substandard printing results.

At shirtworks we use 2 varieties of screen to produce bespoke patterns and designs. They include ‘fixed system screens’ and ‘self-tensioning screen systems’. Fixed screens are the classic frame and mesh glued into place, whereas the self-tensioning screens allow you to adjust the tension as it wears over time.

There are pro’s and con’s to both screen varients. The fixed screen will allow you to achieve a safer and more controlled stretch of the mesh, creating tighter tension than self-tensioning with lower risks of breakage. However once the tension has gone in the fixed frame mesh it is no longer able to be used and a new mesh must be added to the frame.

The self-tensioning screen allows you to tighten the mesh as it ages or becomes slacker, this can prove challenging to ensure tension is the same in both directions. However it is a quick and efficient process.

Applying the Design to the Screen

Prior to images being ‘burnt’ onto a screen, the screen must be coated in liquid emulsion to take on the shape of the design.

Emulsion is applied thinly to the mesh and is dried in a heat controlled environment. Once dry, it is placed on a light box to begin the process of burning the chosen image to the screen. The image has previously been printed onto a clear plastic sheet called an acetate or a separation. This can be done using a desktop printer or an image-setter.

Next, the image is placed on top of the light box, with the screen placed over it and the whole thing is then closed and vacuum sealed.

To begin burning the image, the screen is exposed to UV light to allow the emulsion and the light to chemically react producing a hardened and non-water soluble. Each colour in a design requires this process and when complete up have a number of screens that are placed into a screen carousel in the correct order to achieve a desired outcome. This is known as ‘setting up’ and takes us nicely into our next section.

Setting up

When setting up, the experience and knowledge of the operator comes into play. A mistake at this stage can result in dramatically different results, or a complete fail all together. Thankfully, the team at Shirtworks have decades of experience in screen printing.

A print carousel is a circular construction made from steel, aluminium and plastic. It takes on average about 5 minutes to set up each colour onto the carousel, this includes adding the ink. Therefore it may take up to an hour to set up a 10 colour product, however, many variables can come into play, sometimes making the process longer.

There are 2 different types of carousels, manual and automatic. An automatic carousel can print up to 600 shirts an hour, whereas a manual can print up to 120 an hour, depending on the experience of the operator and the particular job at hand.

When setting up each screen will be slotted into the carousel in the correct order so that each one can be printed sequentially onto the garment. Once in position they are registered to a template to ensure that they are all printed to the correct area of the design. Each colour needs to fit together like a jigsaw to ensure each colour comes together to complete the correct image.

The final part of setting up involves fitting the squeegees into the print head and inserting the ink.

The Ink

In this next section we will discuss the ink, which type to use and the final result of each. The ink you choose is the liquid carrier of the design and allows the customisation to take shape. The type of inks used will either be an oil based plasticiser or water based. Most t-shirt printers tend to choose the oil based option as they can be easier to work with, resulting in a quicker and simpler process. However oil based can be an unattractive option to more ethical buyers, therefore a new type of ink has become available that is more environmentally friendly, offering an alternative for those wishing to source more ethical products.

Water based can pose a problem during the printing process, it can dry out in the screen resulting in precise detailing and colour matching very difficult to achieve. However water based ink will have a softer feel but will lack the vibrancy and long lasting component that oil based inks offer. If a complex design is required oil based ink will be better suited.

Once the ink is chosen and is laid onto the garment it now needs to be cured. Both ink options require a long tunnel dryer to begin curing. A specific time and heat is set, usually about 160 degrees celsius for about 2 minutes.

Applying Ink to Garment

The screen being used basically acts as a stencil, allowing ink to pass over the screen and when removed, you are left with the chosen design. The ink is squeezed or ‘sheared’ through the stencil with a squeegee.

The squeegee is made from rubber, however, it has a sharp edge allowing the ink to be forced through the stencil aperture in a smooth, controlled stroke. A drag of the squeegee over the stencil screen allows you to spread the ink, being careful to spread evenly. This is known as a squeegee stroke. This may need to be repeated two or three times to ensure maximum ink coverage.

Sometimes the ink can be partially cured whilst on the screen carousel, allowing another squeegee stroke of ink to be completed over a more stable surface. This can result in a brighter or thicker deposit, depending upon the desired look you are hoping to achieve.

You should now have a good understanding of screen printing, the process involved and whether it’s the right choice of printing for your custom clothing requirements. However, if you have any further questions regarding screen printing, feel free to get in touch with our friendly UK-based team today, and we’ll be happy to answer any questions you may have.