In a nutshell litho printing uses wet ink and printing plates whilst digital printing uses toners on a smaller press. Digital printing is more suitable for shorter runs and litho printing for longer runs.
The inked image is transferred from a printing plate to a rubber blanket and then the image is transferred again to the paper. Generally the printing will be done out of the standard four-colour process. This means that the artwork is separated onto four different printing plates and each plate prints a specific single colour – Cyan, Magenta, Yellow and Black (CMYK). Together these colours combine to create a full-colour print. Occasionally additional printing plates might also be added to print spot colours. These may be special inks such as fluorescent or metallic or a specific Pantone ink that matches a corporate colour. Similarly, there might be fewer colours used such as two-colour printing where only two specified colours will be printed, and because only two printing plates are being made this is cheaper than four-colour litho.
• A significant area of cost is attributed to ‘making ready’ the job – ie the cost and time involved in making the plates and in running the ‘spare’ material that is required until all the plate images are in register and the job can be run. However, once this is done the cost per copy will be cheaper than digital printing on longer printing runs.
• Because a significant area of cost is attributed to making ready the job – ie the cost and time involved in making the plates and in running the ‘spare’ material that is required until all the plate images are in register and the job can be run, litho printing is not suitable for short-run printing as it is not cost-effective.
• Printing is not limited to four colour process - special or spot inks can be included to enhance the item.
• Litho printing is much better for large areas of solid single colour. The colour comes out smoother and no pixels can be seen.
• The turnaround time is longer with litho, usually a 5 working day average. This is because time has to be allowed for the ink to completely dry before finishing and longer run jobs have to be scheduled to run on the bigger litho presses.
Digital printing is a four colour process reproduction method that uses electronic files (such as PDF artwork) and dots of colour to produce an image using toner. Unlike litho printing no printing plates are required and there is less waste of chemicals and paper because no ‘make-ready’ is required.
• It is very cost effective for small print runs because there is less initial setup involved.
• Quick turnaround as the job is produced in its finished format with no additional drying time required.
• In many cases jobs can be personalised as they are printed with variable data – such as a sequential number, name or address.
Weight of Materials:
In general most digital presses will run paper weights between 80gsm and 350gsm, whereas litho presses will happily run from 60gsm up to 450gsm.
Digital presses are more suitable for the shorter run lengths, generally from a single print up to around 2k (although this figure will vary depending on the particular job specification).
It is generally accepted that digital printing produces a job quicker than litho printing as there is no job make-ready or plate making required.
Historically litho printing was regarded as producing the best quality, and whilst that is still the case for many job specifications digital print quality is now so good that in most cases it is hard for them to tell the difference.
Range of colours:
If specific spot [Pantone] colours are required to a high level of accuracy reproduction then litho printing is the best option.
Personalisation [Variable Data]:
Digital printed items can be personalised. This makes each print unique to the recipient - for example a direct mail campaign could have the name of the recipient incorporated into the design which will increase the response rate.
Metallic do not reproduce very well in digital printing – best stick to litho.