Digital printing – how it works

7/28/2014 9:14:19 am

Printing is easy they say! You just push the start button and that’s it!

We’d love to think it was that easy – our job would be a dream.

But just think of the problems you have with your home printer and multiply these by ten!

Lucky for us, we have many skilled print operators, (in both offset printing and digital) working on the complex machines that do so much more than just put ink on paper.Tony Dorans is one of them who works in the digital print department and he’s been so kind as to take us through how your hard work becomes a work of art!

Digital printing – how it works

Digital printing - how it worksHi, I’m Tony, Digital Supervisor at Elanders. I’ve been in the print trade since I left school, serving my apprenticeship in the prepress department and running printing presses.

I’ve worked for Elanders now for 19 years, starting off in the prepress department as an Apple Mac operator and then becoming Supervisor after a couple of years. Then I was given the opportunity to run the digital presses.

I get great satisfaction from seeing the finished product on paper and knowing that we’ve helped our customers with their communications.

But how do we do it? Well, we can’t tell you all of our secrets, but we’ll guide you through the things you need to know.

There’s a lot we need to do before we press the print button – it all starts with prepress.

Once we receive the file we need to make sure that it is set-up correctly.  For a job to print with a nice clean and sharp image you need to ensure that the images and file are saved in a high enough resolution. Industry standard is 300dpi.

A standard screen views at 72dpi so although the picture views ok on screen it doesn’t necessarily mean the image will be sharp when printed. Pictures also taken by camera or phone need to be on their highest settings. Just because you can take 10,000 images on your camera doesn’t mean that you’ll be able to print any of them to the quality of a decent photograph.

You also need to make sure you have tick marks and bleed. Tick marks are the lines on the corner of your job.  After trimming, the bleed ensures that no unprinted edges occur in the final trimmed document. It is very difficult to print exactly to the edge of a sheet of paper/card so, to achieve this, it is necessary to print a slightly larger area than is needed and then trim the paper/card down to the required finished size.

If all this is correct then we move on to the next stage which is imposition. This is a process of using up as much of the paper as possible to make the job efficient.

The digital presses we use print on an SRA3 paper and we work out how many of each version of your work we can fit onto this, with as little wastage as possible.

Once all this is done, the file is saved and sent to the press.

Most of the printed matter that you see in your everyday life is printed from only four colours. If you take a magnifying glass and look closely at a newspaper or leaflet, you will see the following colours; cyan, magenta, yellow and black. Some shades however, can not easily be made from these colours (but not impossible completely) and therefore a special ink has to be made (metallic etc).

And this is before we start printing!

Firstly I’ll give you an insight into the press. We print on HP Indigo digital presses. We have a multi-colour press which holds the standard four colours I mentioned earlier.There can also be a spot colour or special colour (a bit like the Dulux advert; give us a sample and we’ll match it – just don’t go cutting bits off peoples clothing when they’re not looking!)

We have special colour books that you can match to, so whatever it is your’re looking for, we can do it.

You can also run a white ink which is ideal for window stickers or printing on a metallic board.

The press runs from an 80gsm thin paper (which is great for thick books with lots of pages) up to 400gsm board (invitations and cards etc) but it doesn’t stop there.

We can also run sticky back labels transparent films, silver board and a whole host of exciting materials.

The press has four paper trays but we can run from different trays at the same time. So if you want to print a book that has perforated stock or carbon paper within this, we can do it.

The great thing about the HP Indigo is the wet ink, unlike other digital presses which are toner based (toner based presses lay ink on top of the paper instead of being absorbed into the paper). The benefit of the wet ink being absorbed is that it doesn’t bulk up as you print. If you print a book using toner presses it ends up being a lot thicker because of the toner build up.

How the press prints

The press prints by writing the image to a digital plate. It starts by the writing the yellow, erasing it and then writing the magenta, erasing it etc…each time transferring the plate image to the paper before erasing it for the next, until all four colours are printed.It then delivers the paper to a tray at the end of the press.

My favourite thing about the press is that you can personalise

With the press writing and erasing the image every time it prints, it allows you to personalise really easily. So if you have a letter which you want to address to 10000 people, all you have to do is provide the letter as one pdf and show us where you would like the name changes. Give us a file with 10000 names and address on and well do the rest.

As the press prints, it links to the file with the names on and substitutes the text on every sheet it prints. It doesn’t end there though; you can also incorporate photographs so that the press will even add a different photograph on every sheet it prints. The opportunities are endless!

Once the job is printed we cut it to size then it’s off to the despatch department.

My favourite jobs are those that we run for professional photographers such as calendars. I love photography myself, so getting the chance to produce a beautiful calendar with high quality photographs, knowing that it’s going to be hanging on the owners’ wall for the year is a great privilege.

So that’s digital printing from start to finish, and everything in between. We hope you’ve got a greater understanding of how it works, and more importantly, what fantastic possibilities it holds for your work and what Elanders can do to help you get exactly what you need from your print.

If you have an idea that you think we’d be able to help with using digital print, let us know by email or call 0191 280 0400 and we can talk you through your options.

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