Outside and inside printing: how it works and which materials it is available for

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With Packly, you can customise not only the outside of your packaging, but also the inside. Inside-outside printing (sometimes also searched as “front/back printing”) lets you print full four-colour process on both the outside and the inside of the pack.

Available materials

Inside-outside printing is available on a wide range of Packly materials, with a different production technique depending on the material chosen: solid paperboard or E-flute. When using E-flute, the result is far superior to direct printing on standard corrugated board, as it is laminated with white SBS on both sides: the uniform print base enhances the four-colour process with sharper colours and significantly higher contrast. Moisture-resistant SBS does not support printing on the inside: it is compatible with outside printing only.

How the two sides are produced, depending on the material

Solid paperboard

Inside-outside printing is produced on the same sheet, on the front and back of the paperboard respectively. Pay close attention to the correct orientation of the artwork between the outside and the inside, and to the parts that remain hidden once the box is closed. Colour rendering may vary between the two sides, even when using the same CMYK values. Keep the die-cut template and the page size unchanged. Upload a single PDF, exactly as provided by Packly.

E-flute

Inside-out printing is produced on two separate sheets, which are then glued to the two faces of the flute.
For the inside artwork, favour solid colour backgrounds, patterns or textures: they reduce the perception of any registration shifts between the two sheets.
Avoid, especially close to cuts and folds, frames, borders, lines or graphic elements that require very precise alignment.
Keep a safety distance of 10 mm between text, logos and important graphic elements and the cutting and/or creasing lines.
Note on colour rendering: SBS and FBB paperboard have a glossier, coated outside and a more natural, less coated inside surface. This difference results in different colour rendering between the outside and inside printing, even with identical CMYK values.

How to correctly align the outside and inside artwork

When preparing your files, remember that the layout of the inside artwork is not a simple copy of the outside one: it corresponds to the box panels as seen from the inside, so the order and orientation of the panels between the two files are not a 1:1 mirror image, but follow the correspondence between the faces of the die-cut template (for example, outside panel A corresponds to panel A visible once the box is open, and so on).

Points to check before uploading your files

Consistency between corresponding panels: colours, graphic blocks and identifying elements must be in the same relative position in both the outside and the inside file. A discrepancy between the two versions (for example, a shifted colour block) creates a visible inconsistency once the box is open.
Continuity of patterns and textures on the flaps: if you use patterns or textures, the artwork must continue seamlessly over the rounded areas of the flaps and near the cuts; a visible interruption of the pattern in these areas is a common mistake.
Areas not visible when the box is closed: these still need to be handled correctly in the file, even though they will not be seen on the finished product.

Technical specifications for the artwork file

For the technical specifications on how to set up the artwork file correctly and make it suitable for printing, see the article Printing files: guidelines and suggestions.