What is Screen Printing?

Shirtworks

Screen printing is a great process for larger order of printed t-shirts (10+) and larger designs. Screen-printed t-shirts wash well and can maintain the print quality for some time. Most printing you see in the High Street shops will have been printed this way. although digital printing has become popular for photographs on shirts recently.

This process should not be confused with heat transfer printing (or thermal prints). Transfer prints do not last as well and are not as good in terms of print quality.

When screen printing, one colour at a time is applied and therefore the cost will increase with each additional colour applied. For each separate colour an additional screen is required, so a design with 4 colours in it will need 4 screens, this can make screen printing in many colours uneconomical if only a small run of clothing is required and digital printing might be a cheaper option. At the other end of the number scale the cost of 4 screens spread over a large number of garments doesn't add a lot extra to the cost per shirt. We have price breaks at 10, 20, 50, 100, 200 and at 500. If you want more than 500 then we will produce a bespoke quote for you. You can combine garments to get to the next price bracket as long as the print remains the same. If the print size is changed then this counts as a separate print run. If you would like ot see how we make our screens then check out our screen making video that is on our blog

T-shirt printing is an art form

One thing many customers do not realise is that screen printing is very much an art in more ways than one. Not all t-shirt printers or promotional clothing printers take the same care over the quality of the printing as we do. We make sure our print doesn’t crack, colours don’t overlap, the design is straight and the ink is thick enough.

Types of screen-printing ink

Plastisol printing

Plastisol inks are the standard ‘go to’ inks for most screenprinting jobs.

It is an oil based ink formulated into PVC molecules and pigment, suspended in a plasticizing emulsion.

The ink does not dry out at any point but needs to be cured at approx 160 degrees Celsius for 2-3 minutes for the PVC and plastisiser melt and bind to each other to create a hardened compound.

Plastisol inks tend to sit on top of the t-shirt fibres rather than sink into them and this creates a raised and textured feel.

Dark garments require a heavier deposit than light garments and this exacerbates the ‘raised’ feeling.

This feeling can be mitigated slightly with additional softening agents but this stretches the pigment slightly and reduces the vibrancy slightly.

If the ink is used straight out of the container, it is very opaque and this means your prints achieve a brightness and vibrancy that is superior to all other types of inks.

Plastisol inks are also very versatile with special effects.

You can create interesting textures with ‘puff additives’, glitter, suede effects, cracked effects, metallic and pearlescent effects.

examples of different plastisol inks

 

Plastisols will work on almost any standard fabric used in garment production and this is why they also remain the firm favourite

Waterbased printing

Waterbased inks are popular for two reasons.

  • For ethical reason. The Soil Association has approved waterbased inks on the basis that they offer a better, healthier alternative over oils/pvc products.
  • They are softer to the feel than plastisols.

When printing onto white shirts they will give an almost ‘invisible to the touch’ effect as the pigment soaks into the fibres of the garment while the water dries or evaporates during the curing process.

They are trickier to work with from a technical standpoint as they tend to dry out in the screen during long print-runs and they have difficulty with high mesh count screens, which makes printing gradients a little trickier. For this reason, we may suggest plastisols for tonally variable work.

They work best on 100% cotton garments and work with limited effect on cotton/poly mixtures.

When printing onto dark shirts, water-based inks need a magic trick to make them work.

This is the next subject.

Discharge printing

Example of discharge ink

A bleaching agent is added to water-based inks, which removes the colour from the garment precisely where the ink sits so that the pigment settles onto a neutral colour. This happens in the dryer when the ink reaches the required temperature.

The results can be excellent with 'thin' ink deposits and fairly vibrant colours. This contrasts with the thick deposit required with plastisols to achieve the required brightness.

Plastisols will always win on brightness but many designs were created to look 'vintage' and this is where discharge printing can become relevant.

 Conclusion

· Plastisol works on everything if you are OK with a slight 'feel' to your print.

· Plastisol gives you more special effect options.

· Plastisol gives you more vibrant colours

· Plastisol is better for halftones

Pros and cons of screen printing

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Pros – Great for orders of 10 printed t-shirts or more; high quality, long-lasting print.

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The cons – Relatively high set-up cost on orders fewer than 10 printed t-shirts, particularly if there are a lot of colours in the design.

 

We have a chart showing when is it best time to use screen printing compared to digital printing based on price on our bl