Double-Sided Labels: The Same Technology Behind Share a Coke, Now Printed in Darwin

Every label has a front. Ours also have something to say on the back.

Colemans Printing has been producing two-sided, or “sandwich printed”, labels: a design on the face, and a second, independent print run on the reverse. It’s a technique most people have never seen, since most people have never had a reason to peel a label off a product and look underneath. When they do, on this job, they find a short line of intent: *I stay calm under pressure. I am disciplined in my habits. From file to finish. Print smarter, not harder.

It’s a small detail, and it’s also a genuine capability most commercial printers in Australia don’t offer. It’s built on the same digital press technology that Coca-Cola used to print 800 million personalised bottle labels for its Share a Coke campaign.

Why this one stayed with us

Most print jobs end when the label leaves the press. This one didn’t. Somewhere between the concept and the finished roll, this job stopped being about label stock and started being about the person holding the product. A short line of encouragement, printed somewhere they weren’t expecting to look, is a small thing to manufacture and a genuinely warm thing to receive. That’s the part of this project our team is proudest of: not the press specs, but the moment it creates for someone who was never meant to see the work that went into it.

What is “sandwich printing” on labels?

Sandwich printing (also called double-sided or duplex label printing) is exactly what it sounds like: the label substrate is printed on the front, then printed again on the back, in a separate pass, so both sides carry independent artwork. The two print runs are registered to each other with precision, which matters when the front and back need to align, or when the reverse copy needs to sit correctly under an adhesive layer or clear laminate.

It’s different from a standard label with a printed liner or backing sheet. In duplex printing, the label material itself carries content on both faces. That opens up label real estate that’s usually wasted. Batch codes, compliance text, and terms and conditions on the back are the common commercial use. Colemans has taken the same technique somewhere more interesting: a message, printed for the person who eventually holds the product, that they were never expecting to find.

The technology: HP Indigo, and what it has in common with Share a Coke

Coca-Cola’s Share a Coke campaign is the most cited case study in variable data printing (VDP), the process that lets every individual label in a print run carry different text or imagery, pulled from a database, without a single plate change. Between 2011 and its various global rollouts, converters ran the campaign across HP Indigo digital presses, producing hundreds of millions of uniquely named labels at commercial speed.

Colemans runs the same core technology, HP Indigo digital press hardware, driven by variable data workflows, from its production floor in Darwin. That matters for two reasons. First, it means the quality and consistency benchmark is the same one a business turning over billions of dollars in FMCG uses: sharp registration, consistent colour, no drop-off in quality at label 1 or label 100,000. Second, it means a genuinely global-standard capability is sitting in the Northern Territory, not flown in or outsourced interstate.

That’s the real story here. It’s not that a small label run had a nice idea on the back. The press technology behind one of the most famous personalisation campaigns in marketing history is doing production work in Darwin, available to any Colemans client who wants to use it.

Why put a message on the back of a label at all?

Most packaging talks *at* the customer, and almost none of it talks *to* them. A front label sells the product. A back-of-label message, unexpected, personal, easy to miss unless you’re looking, does something different: it creates a moment. For a wellness brand, a retail loyalty program, a corporate gift run, or an internal staff campaign, that moment is the point.

The same variable data engine that let Coca-Cola rotate 150 names through a production run can just as easily rotate through a set of affirmations, a sequence of instructions, a QR code tied to a loyalty system, or a batch-specific compliance line, all without slowing the press down or requiring a new plate. Once the workflow exists, the content on the reverse becomes a design decision, not a production constraint.

A project built on collaboration

Colemans CEO Magdaline Coleman was quick to point out this wasn’t a solo effort. “I can’t take the credit for this idea,” she said. “Our Head of Creative, Michelle, and our Head of Labels, Mikey, designed the theme, wrote the words of confidence and the aspirational quotations, and made it all happen together. It was a great project of collaboration between our teams.”

It’s a fitting note for a job that’s ultimately about connection. The same instinct that had two teams sit down together to write words of encouragement is the instinct behind the finished product: print that does more than its job description.

Practical applications for NT and Australian businesses

• Retail and FMCG brands – wanting a Share a Coke style personalisation run without sending the job interstate or overseas.
• Corporate and government communications – using the reverse of a label for compliance text, tracking codes, or multilingual information, freeing the front for clean branding.
• Event and promotional products – where a second message, a sponsor logo, a safety instruction, a call to action, needs to sit on the same label without competing with the front design.
• Employee and internal culture campaigns – where a short, consistent message reinforces a value or standard across products, kits, or packaging touching every staff member.