How can you produce high-quality packaging? How should you prepare your graphic files for printing? Brand owners in control of their packaging prepress benefit from increased compliance and reduce their time to market.
Understanding packaging prepress – the basics
An integral part of the printing industry, packaging prepress occurs between a design’s approval and its printing. It’s a crucial step that brand owners usually subcontract to their printers. Alternatively, they may use a packaging prepress agency (sometimes known as a premedia agency or a repro house).
During packaging prepress every detail of a design is checked to:
- Detect any errors
- Retouch and enhance images
- Prepare files for a successful print run
The stages of the prepress process
Here are the principal steps of packaging prepress:
Preparing the artwork
Packaging design artwork is usually prepared by an external graphic design agency. An agency must supply source files in a vector file format like high-resolution PDF with a minimum resolution of 300 dpi (at 100%) for good-quality print production.
Once a brand owner approves a design it is sent:
• Option 1: to its printer, who will often subcontract the packaging prepress process
• Option 2: to a repro house to handle the packaging prepress
This is usually done by email. However, more companies are using packaging prepress platforms to facilitate and accelerate approval and feedback loops for the various departments involved in the process (e.g., marketing, purchasing, quality assurance and compliance) and any external suppliers like:
• Packaging design agencies who can upload design files to the platform
• Printers who can access proofs on the platform
Once safely received, prepress operatives will conduct a series of ‘preflight’ checks including:
• Checking for any missing fonts
• Swapping spot colours for CMYK
• Identifying low-resolution images that need to be re-submitted as vector files
• Spotting details like insufficient bleed margins and poorly placed crop marks
Prepress experts work on the submitted graphics file to enhance the final printed product.
Colour management
Colour management is central to packaging prepress. A particular colour is often what we unconsciously look for when we’re in the supermarket or scrolling product descriptions online. Brands use colour as part of their identity and any deviation from this can have a negative impact. If a packaging colour doesn't match a brand identity or the rest of a product’s range it will need to be reprinted – incurring extra costs and prolonging time to market.
With this in mind, it’s a good idea to set up ICC (International Color Consortium) profiles on monitors used at prepress as this will give the best possible match between digital images of the design and the colours of the final product. An ICC profile communicates with the printer and tells it what colour adjustments to make to print the colours seen on screen.
Image retouching and enhancement
Images used on packaging need to be high-quality to avoid any negative impact to the brand. Prepress photo editors use specialist software to retouch and enhance images so they’re sharp and coloured perfectly to elevate your packaging design. Techniques include contrast correction and colour balancing to pinpoint colours.
Layout and imposition
The positioning of graphic elements (layout) needs to be clear and well-designed. At prepress, details like line splits, font spacing and image size are all reviewed. They will also check that all content is positioned within the safe area of the design.
Imposition is how a print job is arranged on the printing sheet. It’s concerned with printing as efficiently and quickly as possible.
Step and repeat
In prepress, ‘step and repeat’ is a technique used to print several images at the same time. In reprographics, offset and litho printing plates are generally exposed in the CTP or CDI (Cyrel Digital Imager) with a text resolution of 2540–5080 dpi to create a pattern or an image. Step and repeat techniques allow a single printing plate to feature several images so they can all be printed in a single pass.
It’s a common technique in printing and label printing when several images need to be reproduced simultaneously. Step and repeat reduces production costs by allowing several elements to be printed in a single print run. This can also improve printing efficiency, particularly for large-scale printing.
Proofing and approval
Technicians ask the client to confirm that everything is correct before creating a physical proof in a high-definition PDF format, against which the print job will be checked.
Some brand owners request a ‘print proof’. This is a physical proof that is as close as possible to the item the printer will produce, using the planned ink and stock. This gives Packaging Managers a chance to experience exactly how the finished product will look and feel.
Producing printing plates
For non-digital print runs the printer will need the repro house to convert the graphic files into printing plates or sleeves which they will mount onto the press. The printer needs a plate or sleeve for each colour.
Quality control
Prepress operatives use specialist software to check the files for creating printing plates that match the repro quality proof. They’ll also check image quality and resolution.
Sending to print
The repro house will send the final proof to the brand owner’s printer which they will use as a template for the print run, along with the printing plates.
The benefits of an effective prepress process
For ambitious brands, a well-organised and skilful prepress process is invaluable to enhancing their packaging. It positively impacts the bottom line in terms of saving time and money.
Why should brands prioritise better packaging prepress processes?
The main objectives are to:
• Scale and speed up printing
• Reduce time to market
• Optimise printing costs
Taking the next step
A major prepress operator in Europe, Miller Graphics works with brands to optimise their packaging design process, from design-to-print service.
Find out how you can optimise your packaging prepress process, book a call with one of our experts in design processes.
