Digital vs Litho Printing
On a lithographic press, an aluminium printing plate is first coated with water which is repelled by the image, followed by a coating of printing ink which is repelled by the water thus “inking up” the required image. This image is then transferred to the paper via a system of transfer rollers.
This method is fast and extremely accurate. Ink dots can be incredibly small in litho printing ensuring extremely fine detail can be reproduced. Our Heidelberg presses have fantastically accurate registration which means every one of these tiny dots lands in exactly the correct place on each passing sheet of paper – even if the sheets are whizzing through at a rate of 15,000 per hour.
By contrast, a digital printing press uses toner, transferring the image to the paper using positive and negative electrical charges. Digital presses are constantly improving but cannot remotely emulate the sheet speed of a lithographic press. The quality of digital print is now very good and comparable to litho for colour pictures. Digital printing is limited to four colour process (CMYK) What is CMYK whereas a lithographic press can be loaded with any one of thousands of coloured inks (see SPOT COLOUR PRINTING).
Why not use lithographic printing all the time?
Simple answer: because digital printing is extremely cheap to set up in comparison. For each colour used in lithographic printing, a separate plate and inking unit is required. The production of a plate and the skill required to set up the inking units does, unavoidably, have a higher basic set up cost.
As a result, digital will always work out much cheaper on shorter runs and litho much cheaper for higher runs. Therefore the two process complement each other ensuring that whether you want 50 invitations or 10,000 brochures – we have the means to produce them by the most efficient method.
Spot colour litho printing
Our lithographic printing service has another major advantage over digital printing – we can match any one of thousands of Pantone® colour inks. Fewer and fewer printers offer this service these days as it is a specialist skill. Spot colour printing is alive and well here at Gowise – read more on our dedicated page Spot Colour Litho Printing
Digital Toner vs Litho ink
We have seen that using spot colours, litho printing can produce a huge range of colours accurately whereas digital is limited to the CMYK gamut. In addition, the way each of the two processes introduce that colour to the paper is quite different – giving advantages for and against each.
Lithographic ink, being a “wet” process, will require time to dry. Digital toner is fused onto the paper with heat and is dry and ready for finishing at the point it leaves the machine. Lithographic ink will sink into the paper as it dries which may affect the colour and the overall look of the print (which may or may not be preferable). Coated papers were developed to help litho ink remain on the surface of the paper as it dries.
As digital toner is fused to the paper, it is instantly dry and remains on the surface regardless if it is printed on coated or uncoated paper. This will mean that litho and digital print can look quite different on the same paper – particularly if the paper is uncoated. Again, this may or may not be desirable. Our Xerox digital press has a very natural look, but as it fused onto the surface, a large area of colour will always have a slight sheen to it. A litho colour may not.
You may imagine, correctly, that there are many other slight differences in performance between digital and litho and far too many to detail here. The key factor is usually the run length which gives a clear winner on price – but there are occasions where certain jobs will look better run digital than litho and vice versa. Rest assured, we are here to advise and can provide printed proofs where necessary.
The following table provides a brief overview but there is one big thing that digital can do that litho cannot….Variable Data.
LITHO VS DIGITAL AT A GLANCE
| LITHO | DIGITAL | |
| COST-EFFECTIVE FOR VERY SHORT PRINT RUNS | NO | YES |
| COST-EFFECTIVE FOR VERY LONG PRINT RUNS | YES | NO |
| PRINTS IN FOUR COLOUR PROCESS (CMYK) | YES | YES |
| ACCURATE SPOT COLOUR PRINTING | YES | NO |
| METALLIC COLOUR INKS AVAILABLE | YES | NO |
| INSTANTLY DRY | NO | YES |
| VARIABLE DATA PRINTING AVAILABLE | NO | YES |
| PRINT HAS THE SAME FINISH ON ALL PAPERS | NO | YES |
| PRINTS WELL ON TEXTURED STOCKS | YES | NO |
| CAN PRINT USING TINTS OF COLOURS | YES | YES |
| GOOD QUALITY PICTURE REPRODUCTION | YES | YES |