Preparing Artwork for Custom Printed Paper Bags: A Pre-Press Checklist

Most delays in custom printed bag orders trace back to one thing: artwork that arrives in the wrong shape. Not bad design — wrong files, wrong colors, or a layout that ignores how a bag folds. This checklist covers what our pre-press team (and any flexographic printer) needs, so your first proof is also your last.

1. Send vector files, not photos of your logo

Flexographic printing plates are made from vector paths. Send your artwork as AI, EPS, SVG, or a press-quality PDF with live vectors. A JPEG or PNG of your logo — even a large one — must be manually redrawn before plates can be made, which adds days and introduces interpretation errors.

• Convert all text to outlines/curves before exporting, so missing fonts can't reflow your design.
• If a raster element is unavoidable (a photograph, a texture), supply it at 300 DPI at final print size — and expect us to flag it, because fine photographic detail is not flexo's strength.

2. Specify colors as Pantone, not screen values

Flexo prints with pre-mixed spot inks, so the reliable way to specify brand colors is Pantone (PMS) references. RGB and hex values describe light on a screen, not ink on paper, and CMYK builds behave differently in flexo than in digital printing.

Two things to know about printing on kraft:

• Brown kraft tints everything. Inks are semi-transparent, so a yellow logo on brown kraft shifts olive; light colors lose vibrancy. Options: choose darker ink colors, print a white underbase (adds a color station), or switch to white kraft for color-critical artwork.
• Count your colors. Each color is a separate plate and print station — one- and two-color designs are the flexo sweet spot for cost and consistency. Ask us before committing to a six-color gradient.

3. Design for the bag's geometry

A bag is not a flat rectangle. It has front and back faces, side gussets, a base fold, and — on handle bags — a top fold where the handle patch attaches. When you send artwork, we place it onto a dieline of your exact bag size and return a dimensioned proof. To avoid surprises:

• Keep critical elements (logo, contact details) on the front face, at least 20 mm from folds and seams.
• Artwork that wraps around gussets will cross fold lines — fine for background patterns, risky for text.
• The rear face carries a glue seam down the middle; avoid centering fine artwork on the back.
• Full-coverage ("flood") printing is possible but costs more ink and shows scuffs more readily than spot placements.

4. What we send back, and what we need from you

Within a few days of receiving your files you'll get a print layout proof: your artwork on the bag dieline, with dimensions, Pantone callouts, and print positions marked. Review it for spelling, placement, and colors, then approve in writing — plates are only made after sign-off. For color-critical brands we can produce a physical strike-off sample on your actual paper stock before the full run.

5. Common mistakes that cost a week

1. Logo sent as a screenshot from a website (see #1).
2. Brand color given as "our blue" with no Pantone reference.
3. Fine 6 pt text or thin serif strokes — flexo on kraft holds detail down to roughly 1 pt lines and 8 pt text; smaller than that risks filling in.
4. Solid black coverage over large areas without discussing ink and scuff trade-offs.
5. Approving a proof on a phone screen and noticing a typo after 50,000 bags print. Read proofs on a large screen, twice.

Handing over: the checklist

• ☐ Vector file (AI / EPS / SVG / vector PDF), text outlined
• ☐ Pantone references for every color, or physical sample to match
• ☐ Bag size confirmed (width × gusset × height) so the dieline is right
• ☐ Placement instructions (front only? both faces? gussets?)
• ☐ A contact who can approve proofs quickly