Start with the production structure
Packaging artwork is designed for a three-dimensional object but normally handed over as a flat file. A dieline shows how that flat material is intended to become the package. Depending on the format, it may identify cut lines, folds or creases, glue areas, panels, and other structural features.
Ask for the latest production dieline for the structure and size being quoted. Confirm who supplied it, its version, the measurement units, and which marks represent cutting, folding, glue, or non-printing information. A rendered box mockup is helpful for visual review, but it is not a substitute for a confirmed production dieline.
Put artwork on the correct panels and check orientation when the package is folded. A panel that looks upright on the flat sheet may be inverted in the assembled box. Keep structural marks distinguishable from printable art in the working file, following the production team’s file instructions. If a structural change occurs after artwork has been placed, review the affected panels again rather than reusing the previous file by name alone.
The final production tooling and dieline must be confirmed with the manufacturing side. A preliminary layout cannot approve a cutting tool.
Bleed extends artwork past the cut
Bleed is artwork that continues beyond an intended trim or cut edge. It gives a background colour or image room to reach the finished edge despite normal cutting variation. If a blue background ends exactly at the cut line, a slight trim shift may reveal an unwanted unprinted strip.
Bleed is different from the safe zone. The safe zone keeps important text, logos, barcodes, and other critical content away from edges, folds, or areas where production variation could make them hard to read or alter their appearance. Bleed goes outward beyond the cut; the safe zone sits inward from relevant boundaries.
Use the bleed and clearance values supplied for the confirmed production dieline and specific production requirements. A common number found in a design template is not automatic approval for another package. For a small label, a rigid box wrap, and a folding carton, the practical checks may differ.
Check the artwork itself, not only the document size. A larger canvas does not help if the background stops at the intended cut. Conversely, a file may contain enough image beyond an edge but still place critical text too close to the fold or trim. Both need review.
“DPI” means checking detail at final size
Design teams often say “DPI” when discussing image sharpness. For a placed raster image, the more precise measure is effective PPI: image pixels divided by the size at which the image will print, in inches. DPI technically describes printer dots, while PPI describes image pixels. The distinction matters because changing a file’s resolution label alone does not create more image detail.
Suppose a photo is 1,500 pixels wide. At five inches wide on the package, it has 300 effective pixels per inch. At ten inches wide, it has 150. The source image did not change; its printed size did. Check the intended placement size, especially when a design enlarges a photo across several panels.
Vector artwork, such as a properly prepared logo or line drawing, behaves differently from a raster photograph: it is not evaluated by the same pixel count. Sharpness also depends on the printing process, substrate, viewing distance, and content. Treat “300 DPI” as a common planning reference, not a universal pass rule. Agree the actual file requirements with the printer or prepress team.
Check colour and file dependencies
CMYK process colour and a specified spot colour serve different purposes. If a brand requires a particular Pantone reference or another named spot colour, identify it in the brief and in the production file as instructed; do not assume a screen appearance or a CMYK conversion will match it. Material, finish, and viewing conditions also affect appearance, so use an agreed colour reference and approval method.
Before handoff, confirm that required fonts are available to the receiving party or handled in an agreed way, and that linked images are present and current. Do not assume that sending a working design file alone includes every asset. Font licensing may limit whether font files can be shared.
Overprint and knockout control how overlapping colours are output. An unintended overprint setting can change the printed result even when the screen preview seems acceptable. Flag special colour, white ink, foil, barcode, small type, and other high-risk areas for prepress review. A buyer does not need to solve every separation issue personally, but the handoff should make such requirements visible.
Control the version that is approved
Give files and proofs clear revision identifiers. Record which dieline version, artwork revision, colour reference, and physical sample or proof have been approved. When copy, structure, barcode, finish, or a regulatory element changes, identify the affected scope and ask for a renewed review. A file called `final_v7_revised.pdf` is not an approval record.
A practical handoff can include the editable file or agreed production PDF, linked assets where applicable, a visual reference, the confirmed dieline, a list of spot colours and finishes, and a short note of outstanding decisions. The exact package of files should follow the receiving production team’s requirements.
Use the tools for an early check
PACKRIVA’s Packaging Print File Checker can make preliminary, local browser checks of supported raster files and buyer-entered dimensions. The Packaging Bleed Calculator helps calculate a canvas size from entered finished dimensions and bleed. The DPI & Resolution Checker helps estimate effective image resolution at an intended print size. The Packaging Artwork Checklist helps organize the wider handoff questions.
These checks do not confirm the final dieline, typography, colour separations, spot colours, profiles, overprint, barcode quality, or manufacturing tooling. A favourable tool result is not production approval. Final production files, prepress checks, proofing, and the manufacturing-side dieline require the responsible parties’ confirmation.
Common misunderstanding
“The image says 300 DPI, so the artwork is ready.” The relevant question is how many pixels the image provides at its final placed size. Even a sharp image cannot resolve a wrong dieline, missing link, insufficient bleed, or unapproved colour.