Litho printing uses ink and printing plates whilst digital printing uses toners on a printing press. Digital printing is more suitable for shorter runs and litho printing for longer runs.
Usually the printing will be done out of four-colour process. The artwork is separated onto four different printing plates and each plate prints a specific single colour – cyan, magenta, yellow and black, the term often used is CMYK. To produce products to a higher specification additional plates may be used to print spot colours. These could be inks that are metallic or a specific Pantone ink that presents as a solid colour and is generally more accurate when used for product branding and are generally more expensive.
Digital printing is still four colour process CMYK however it uses dots of colour to produce an image using toner rather than ink. As digital printing uses toners there can be some cracking when a job is folded and creased, this is more of a problem these days as some clients like to work with uncoated products as they are more environmentally friendly.
Digital printing is great for lower print quantities but will never be the same level of quality of Litho printing. It can however be a reasonable compromise when budgets are tight and print requirements are small.
Litho printing will reproduce tints, gradients and large solid areas of colour better than digital printing. However a significant area of cost is attributed to the ‘make ready’ of the job – (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. The type of paper as well as quantity and budget will also determine whether the product should be printed digital or litho.
In general most digital presses will run paper weights between 80gsm and 400gsm, whereas litho presses will happily run from 60gsm up to 500gsm.
Digital presses are also limited in the types of material on which they can print successfully. Some heavily textured materials do not print very well and gloss papers can look dull if there is full image coverage. Litho presses have a much wider choice of materials available including specialist uncoated stock.