Printing techniques explained

What do pad printing, screen printing and sublimation all have in common? They are a few of the printing techniques that we use here at Loopper. We know that all these techniques can be quite overwhelming, so we designed this guide to take a look at the differences between them and their pros and cons. Hopefully after reading this, you will have a grasp on how these techniques differ and when their use is warranted on your personalised products!  

Pad printing

Pad printing, also called tampography or tampo printing, is an indirect offset printing process where a silicon pad (similar to a stamp) takes a 2-D image from a laser engraved printing plate and transfers it to an object. The stamps are elastic, which means that they easily adapt to an object. Pad printing is the best printing method for objects with 'irregularities', such as round products. It is also suitable for small imprints, such as personalised lighters.

How pad printing works:

1. The closed ink cup sits over the engraved artwork area of the pad printing plate, covering the image and filling it with ink.
2. The closed ink cup moves away from the engraved artwork area, taking all excess ink and exposing the engraved image, which is filled with ink. The top layer of ink becomes sticky as soon as it is exposed to the air; that is how the ink adheres to the transfer pad and later to the product to be printed. 
3. The transfer pad briefly presses down onto the printing plate. As the pad is pressed, it pushes air outward and causes the ink to transfer from the engraved artwork area onto the pad.
4. As the transfer pad lifts away, the tacky ink film inside the engraved artwork area is attached to the pad. A small amount of ink remains in the pad printing plate.
5. As the transfer pad moves forward, the ink cup also moves to cover the engraved artwork area on the printing plate. The ink cup again fills the engraved artwork image on the plate with ink in preparation for the next cycle.
6. The transfer pad compresses down onto the product, moving the ink layer picked up from the printing plate to the product surface. Then, it lifts off the layer and returns to the home position, thus completing one print cycle.

• The 'stamps' are elastic. Therefore, they can easily adapt to any object.
• Pad printing is the best printing method for objects that are round, convex or concave. For example: personalised mugs and personalised pens.

• Pad printing takes a lot of time because of the curing process.

When is pad printing suitable?

Screen Printing

Screen printing is the process of transferring a stenciled design onto a flat surface using a mesh screen, ink and a squeegee. Fabric and paper are the most commonly screen-printed surfaces, but with specialised inks, it is also possible to print onto wood, metal, plastic, and even glass.

How screen printing works:

1. A screen is made from silk, polyester or steel gauze. This screen is stretched over a framework. This is the screen printing frame.
2. The sheet featuring the design is then laid onto the screen, and the whole thing is exposed to a very bright light. The light hardens the emulsion, so the parts of the screen which are covered by the design remain in liquid form.
3. After the screen has been exposed for a set time, the areas of the screen not covered by the design will have turned hard. Any unhardened emulsion is then carefully rinsed away. This leaves a clear imprint of the design on the screen for the ink to pass through.
4. The screen is lowered down onto the printing board. Ink is added to the top end of the screen, and a squeegee is used to pull the ink along the full length of the screen. This presses the ink through the open areas of the stencil, imprinting the design on the product underneath.

• A higher quality output than digital prints.
• Useful for long-lasting prints.
• Can be used on a variety of different materials including glass, wood, textiles and much more.

• Screen printing has a much higher initial setup cost than digital printing and takes more time.

When is screen printing suitable?

Screen printing is most suitable for textiles, like personalised bags and personalised caps.  

Digital printing

Digital printers print the ink directly onto an object. Everything is printed in full colour. Because of this, the resolution is relatively high. The fixed costs per print job can be low, especially for small print runs or rush jobs. Digital printing is an excellent alternative to screen printing, especially when small quantities are involved.

How does digital printing work?

1. The material or product to be printed is laid flat on the board without any creases. If there are any creases, the print will be distorted.
2. The digital printer begins the actual printing by moving the print heads from side to side, on the material, spraying the design on to it.
3. The product is removed from the pallet with great care once the printing is complete. It is then conveyed through a huge dryer at the appropriate temperature, to ensure that the print adheres securely to the item.

• With digital printing, everything can be personalised per piece.
• The fixed costs per printing job can be exceptionally low, especially for small print runs or rush jobs.
• Digital printing is an excellent alternative to screen printing, especially when small quantities are involved.

• If your print project has over 2,500 impressions, digital printing is not a good choice for pricing. A longer print run results in a higher click count, driving up the cost of your project.

When is digital printing most suitable?

Digital printing is perfect for small quantities, rush jobs and articles that need to be printed per piece. This is the process used for most of our personalised notebooks.  

Transfer printing

With transfer printing, the design is applied indirectly to the product.

How does transfer printing work?

1. A mirrored image of the design is applied onto a self-adhesive film.
2. This film is pressed at a high temperature onto your textile.
3. Under the effect of the heat, the ink detaches and fixes itself in the fabric.

• Transfer printing is particularly suitable for flexible materials, such as personalised aprons.
• It is also suitable for detailed prints with multiple colours.
• Another big advantage is that any combination of sizes and colours is possible. Even the tricky 'positions' can be printed, such as the handle of a personalised tote bag.

• A transfer print should not be ironed over.
• The press surface is larger than the transfer. This means that the press surface around the logo can remain visible, even after it has been washed many times.

When is transfer printing most suitable?

Transfer printing is most suitable for products with flexible material, detailed prints, and designs with multiple colours.  

Sublimation printing

Sublimation is a method of printing that transfers a design into a material or fabric using ink and heat. Sublimation is often used for prints with multiple colours, like personalised umbrellas.

How sublimation printing works:

1. The print is applied with a special ink on sublimation paper. The inks that are used turn into gas when brought under heat.
2. The print is then heated and pressed onto the article.
3. The sublimation paper is removed.
4. This leaves only the print on the article.

• The effects are permanent and less prone to fading, as the ink is embedded in the fabric or substrate rather than simply laying on top like a normal print.

• Sublimation printing is only suitable for garments that include polyester (100% polyester or polyester blend). Although sublimation is possible on other materials such as cotton, the image will not be permanent as it is on ‘man made’ fabric and is not recommended.

When is sublimation suitable?

Photography prints perform very well with sublimation. The method allows you to fill the whole surface with the photograph, instead of just placing it on the front of the garment in a rectangular fashion. If you only need one logo in the centre of your product, sublimation may not be the ideal way to go, purely because it’s generally more expensive to print all over than it is to apply one logo front and centre.  

In conclusion

So, you are now a printing option master, right? Just kidding. We know it is a lot of information to take in. But you should have a basic understanding of some of the most common printing techniques we offer. If you still have questions, don't hesitate to contact us or your account manager. We at Loopper are always here to help!