Packaging Preflight Checklist Converters Use

What a converter preflight is meant to catch

Preflight is a controlled review of a supplied file within prepress. It is not a design critique and it is not a press approval. The aim is to catch file conditions that could stop or distort production: missing fonts, unexpected color spaces, insufficient image resolution, inappropriate layer visibility or merging, a misplaced dieline, barcode geometry that conflicts with the agreed placement, and finishing areas that do not line up with the artwork. Prepress operators use professional tools to preflight, preview output, handle transparency, convert colors and manage inks as the workflow requires. Start with the converter's job ticket and applicable production and barcode specifications, not a generic checklist.

Begin with the converter job ticket and file format

Open the job ticket before the art file. Confirm substrate, print process, PDF/X flavor, color targets, named spot colors, dieline layer, printer marks, proof type and any barcode grade the converter wants verified. Industry associations such as the Ghent PDF Workgroup recommend PDF and PDF/X for exchanging packaging and label jobs, according to Adobe's PDF Print Engine packaging paper. That recommendation is a starting point, not a universal instruction. PDF/X-4 can carry color-managed RGB, and the printer's agreed workflow determines conversion. Ask whether RGB is acceptable, whether transparency stays live, and which overprint settings the converter expects.

• Confirm trim, bleed and safe area values from the job ticket.
• Confirm font embedding or outlining rules.
• Confirm layer names and which layers should be visible or hidden.
• Confirm whether the converter wants marks, dieline and annotations in the file or in a separate guide.

Barcode checks to make in the file

Barcode checks are a core part of packaging preflight because a file can look correct and still produce a symbol that scans poorly. GS1 guidance lists check digit calculation, quiet zones, contrast, color choice, symbol construction, symbol size, bar height, packaging interference, deteriorated code and symbol positioning as items to check. GS1 also recommends dark bars on a light background. Reddish colors can work as backgrounds because many scanners use red light, but those colors should be avoided for bars. Bars should be a single line color rather than built from multiple imaging tools. For GS1 symbols, establish the applicable minimum verification grade, aperture and wavelength from the relevant GS1 specifications, along with any buyer requirements, and agree the printed-symbol verification plan with the converter. Exact criteria depend on the symbol and application and are not supplied here. Position depends on the symbol type and the packaging, distribution, storage and handling process.

Color, ink and transparency decisions

Color preflight starts with intent. List every process and spot color, then confirm the converter's ink list. We recommend keeping registration color for printer marks and confirming the converter's preferred black build for artwork, since registration color and rich black are different settings. Actual spot plates apply only to workflows that use plates. Digital workflows can simulate named spot colors, so ask how the proof will represent them. PDF/X-4 can carry color-managed RGB, and the printer's workflow determines conversion, so do not treat RGB as automatically wrong. Check transparency, overprint and white ink setup against the converter's instructions. Adobe states its PDF Print Engine can emulate spot colors on proofing devices and extended color gamut presses, but the proof and approval criteria still need agreement.

Images, fonts and line work

Check images at final placed size, not by the pixel dimensions alone. A large pixel count can still be low resolution if the image is placed large. Confirm image color mode, compression, alpha channels and any linked files. Fonts should be embedded or outlined according to the converter's rule; do not assume one approach fits every workflow. Review small text, fine lines and reversed type on the intended substrate. Adobe describes its PDF libraries as handling font handling and text rendering, but rendering software is not a substitute for checking the file. Make sure barcodes and other critical marks are scaled proportionally, not stretched to fit a panel.

Dieline, layers and finishing alignment

Treat the dieline as a structure guide, not as artwork. Keep it on the layer and with the naming the converter requests. Do not move, scale or redraw it unless the converter asks. Check bleed, safe area, glue flap areas, fold lines and any keep out zones. Finishing elements such as varnish, foil and emboss need to align with the printed graphics. Printer marks, dieline visibility, layer structure and proof type should follow the converter's instructions rather than a universal rule. If you supply a simplified geometry sketch for discussion, label it as a sketch and not as a manufacturable dieline.

Worked example: effective image resolution on a label panel

Use a hypothetical label face that is 100 mm wide by 70 mm high. This is a simplified label panel, not a dieline. A logo is placed 60 mm wide and the supplied image is 900 pixels across. Convert the placed width to inches by dividing 60 by 25.4, which gives 2.3622 inches. Divide 900 pixels by 2.3622 inches to get about 381 ppi effective resolution. If the converter's target is 300 ppi at final size, the required pixel width is 2.3622 multiplied by 300, which is about 708.7 pixels. The 900 pixel image is above that arithmetic threshold. This is an arithmetic estimate, not a print validation. Sharpness, compression, substrate and screening still affect the result.

Proof, approval and handoff checklist

Preflight closes with a proof and a clean handoff. Confirm the proof type the converter wants: soft proof, contract proof or press proof. Compare the approved proof with the exact file version being sent. Record the file name, version, date of approval and the person who approved it, without relying on memory. Use the table below as Teal's editorial planning framework, then replace the pass conditions with the converter's written requirements. The checklist that follows is a practical handoff sequence, not a claim that every converter uses the same steps.

• Obtain the written job ticket and the converter's preflight checklist.
• Place the approved dieline on its named layer and lock it.
• List every printing ink, including white where used, and identify varnish, foil and other finishing separations separately. Match separation names to the converter's instructions.
• Check barcode check digit, quiet zones, contrast, size, height and position.
• Check effective resolution for each image at final placed size.
• Confirm fonts are embedded or outlined as instructed.
• Confirm bleed, safe area, marks and layer visibility.
• Confirm finishing areas align with the artwork.
• Send the exact approved file version with a proof and approval record.

Scope limits and what preflight cannot prove

Preflight is a file review. It does not prove that a barcode will scan on a curved, reflective or wrapped package, that a color will match on the chosen substrate, that a carton will assemble, that a barrier will hold, or that a packed product will survive distribution. GS1 notes that packaging can interfere with scanner access through wrapping, printed borders and similar conditions, and that symbol positioning depends on the packaging and handling process. ISO-based verification assesses printed barcode quality; applicable GS1 specifications establish minimum grades and verifier settings for GS1 symbols. Confirm the relevant specifications and any buyer requirements rather than relying solely on converter preferences. Shipping and carrier rules are separate from print preflight. For regulated products, use a review workflow with the responsible specialist rather than treating preflight as a compliance determination.

Questions about converter packaging preflight