Litho or digital print are the choices for most commercial print jobs. Both have their strengths and cost implications.
For personal stationery and invitations Impact offers thermography through its subsidiary Saint Owen’s Press.
What is Litho-print?
Lithography derives from ‘writing with stone’ from the days when a stone was etched and used as a printing plate.
Working on the principle that oil and water repel one another litho printing today uses a metal printing plate that accepts ink only to those areas to be printed, water filling the gaps.
Litho printing produces a sharp image because the rubber covered Blanket conforms to the small surface variations of paper. If a page was to be printed directly from the plate cylinder the image will be reversed. The offset process of using the Blanket cylinder corrects that, hence litho offset.
What is digital print?
Digital or ‘on demand’ printing is similar to using a desktop printer. Writing, designing and pre-press are all part of the digital workflow. Files go electronically to a printing machine. No film or plates are involved.Typically short run documents from text books to promotional flyers and inserts are the candidates for digital printing.The process offers speed, flexibility and the opportunity for considerable personalisation and variation within a print run.
As the Plate cylinder is rotated – see above – ink is transferred from the reservoir, then transferred again to the Blanket cylinder, and then to the printed page by pressing between the Blanket and Impression cylinder.
The artwork to be printed goes directly from a computer as an electronic file, with no plate needed, to a digital press.
Thermography begins with offset printing. Printed sheets leave the litho press by a conveyor belt and are then sprayed with with a fine resin powder which sticks to the wet ink.
Thermography costs less than engraving and to the untrained eye looks and feels similar.
Pros & Cons
Advantages of litho
- Best for most jobs.
- Accurate pre-press proofs.
- High quality finish.
- A wide range of paper choices and special inks.
- Low unit cost for long runs.
- Start up costs.
- Higher unit costs for short runs.
- Slower turnaround.
Advantages of digital
The process offers speed, flexibility and the opportunity for considerable personalisation and variation within a print run.
- Fast turnaround.
- No start up costs.
- Print only the number you need.
- High degree of personalisation.
- Easy adjustment during print run.
- Higher unit costs for long runs.
- Less accurate pre-press proofs.
- Less accurate colour matches.
- Reduced paper choices and no special inks.