File Format & Technical Requirements
Submitting print-ready files is the single most impactful thing you can do to ensure your packaging prints on time and looks exactly as intended. Below is our complete technical checklist — every category must be checked before sending files.
Print-Ready File Checklist
| Category | Requirement | Why It Matters |
|---|---|---|
| File Format | .AI or high-resolution .PDF | Preserves all vector data and embedded images |
| Color Mode | CMYK for images; Pantone for spot colors | Avoids unexpected color shifts in print output |
| Resolution | 300 DPI minimum for all images | Ensures crisp, sharp printing without pixelation |
| Fonts | All text converted to outlines/curves | Prevents font substitution and missing character issues |
| Bleed | 3–5 mm beyond cut lines | Avoids white edges after die-cutting |
| Safe Zone | Critical content ≥5 mm inside cut line | Prevents logos and text from being cut off |
Pro Tip from Our Prepress Team: Always flatten transparency in Illustrator before saving your final PDF. Hidden transparency can cause unexpected white boxes or missing elements during RIP processing.
Dieline Preparation Guide
What is a Dieline?
A dieline is a flat, 2D technical template that shows exactly how your packaging will be cut, folded, and assembled. It is the single source of truth for your packaging design — every element of your artwork must be placed relative to the dieline.
Paper Bag Dieline — Technical Illustration
Cut Lines (Solid)
Where the material is physically cut after printing
Fold / Crease Lines (Dashed)
Where the material is scored and folded during assembly
Bleed Area (Outer Boundary)
Artwork must extend 3–5 mm beyond cut lines
Safe Zone (Inner Boundary)
Keep all critical content ≥5 mm inside cut line
How to Get and Use Your Dieline
Important: Never scale or resize the dieline. If your dimensions change, request a new template. Scaling causes misalignment between the print and the cutting die — a costly error at production stage.
Color Management & Proofing
Color is one of the most misunderstood aspects of print production. What looks vibrant on your screen (RGB) may print flat or shifted if not converted correctly. Understanding when to use CMYK versus Pantone is essential for color-accurate results.
CMYK
Use for: Full-color images, photographs, illustrations, and most packaging designs. Standard process printing — Cyan, Magenta, Yellow, and Key (Black).
- Cost-effective for multi-color designs
- Suitable for gradients and complex artwork
- Set document color mode to CMYK in Illustrator
- Never submit RGB files for printing
Pantone (PMS)
Use for: Brand-critical colors that must match precisely across all print runs. Spot color inks applied as a single, pre-mixed color layer.
- Essential for logo colors and brand standards
- Ideal for repeat orders requiring color consistency
- Always specify the full Pantone code (e.g., Pantone 872 C)
- Adds cost but guarantees accuracy
Proofing Best Practices
📄 Digital Proof
A high-resolution PDF showing exact layout, colors, and content. First approval step — fast and free.
🖨️ Physical Sample
A printed, assembled sample produced on production materials. Essential before mass production.
🎨 Pantone Matching
We match your Pantone codes on a physical swatch and confirm with you before printing the full run.
✅ Written Approval
Always provide written proof approval before mass production begins. This protects both parties.
For deeper guidance on finish and material color interactions, see our Materials & Printing Finishes Guide →
Setting Up Files for Special Finishes
Special finishes — hot foil stamping, spot UV coating, and embossing/debossing — add luxury appeal to your packaging. Each requires a correctly prepared separate layer in your artwork file. This is one of the most common areas where buyers make costly mistakes.
Hot Foil Stamping
Premium FinishCreates metallic gold, silver, or colored foil accents. Popular for logos, brand names, and decorative borders.
Layer Setup:
Layer name: "Foil"100% black vector shapes only. No raster images. Minimum stroke width: 0.3 pt.
Spot UV Coating
Gloss AccentHigh-gloss varnish applied to specific areas. Creates tactile contrast against matte lamination. Ideal for logos and imagery.
Layer Setup:
Layer name: "Spot UV"100% black vector shapes. Must align precisely with printed artwork below.
Emboss / Deboss
Tactile FinishRaises (emboss) or recesses (deboss) the material surface for a premium tactile effect. Works best on thick stock.
Layer Setup:
Layer name: "Emboss"100% black vector only. Avoid placing near fold lines. Keep details simple.
Finish File Setup Guide
| Finish | How to Prepare Your File | Common Mistakes to Avoid |
|---|---|---|
| Hot Foil | Separate layer named "Foil", 100% K vector only | Using raster images, thin strokes (<0.3 pt), or complex gradients |
| Spot UV | Separate layer named "Spot UV", 100% K vector only | Misalignment with printed artwork, applying to matte-only areas |
| Emboss/Deboss | Separate layer named "Emboss", 100% K vector only | Placing too close to fold lines, using too much fine detail |
💡 Finishing Combinations That Work Well Together
Matte lamination + Gold hot foil is one of our most popular premium combinations. The flat matte surface provides a sophisticated contrast for the reflective foil. For this combination, ensure your foil layer has clean vector edges and is at least 1 mm away from the nearest fold line.
Common Artwork Mistakes & How to Avoid Them
These five mistakes account for the vast majority of artwork rejections and sampling delays. Understanding them takes minutes — avoiding them can save weeks of back-and-forth.
Spec Builder — Copy & Paste Checklist for RFQ
Use this ready-made spec template when submitting your RFQ to Omet Pack. Fill in your details, copy, and paste directly into your email or inquiry form. This ensures our team has everything needed to provide an accurate quote and start your dieline immediately.
| Item | Specification Example |
|---|---|
| Product Type | Paper Bag (retail shopping bag with ribbon handle) |
| Finished Size | W × Gusset × H (e.g., 26 × 12 × 32 cm) |
| Dieline | Provided by Omet Pack (or: Client-supplied, .AI attached) |
| Color Mode | CMYK + Pantone 872 C (gold) |
| Finishes | Matte lamination + gold hot foil on logo only |
| Handle | Satin ribbon, ecru / ivory color |
| Compliance | FSC certified materials required |
📋 Copyable Spec Template
How Files Impact Production Timeline
Incorrect or incomplete files are one of the most common causes of sampling delays and extra costs. Understanding the impact of file quality on your project timeline helps you plan — and submit — more effectively.
Print-Ready File Submitted
Production begins within 1–2 business days of file approval. No delays. Sample delivered on schedule.
Minor Issues (Low DPI, No Bleed)
Our team flags issues and sends correction requests. Adds 2–5 business days for revisions and re-approval before production can begin.
Major Issues (Wrong Color Mode, Missing Layers)
File must be recreated or extensively reworked. Adds 5–10+ business days. May require new dieline or reproof cycle.
Errors Found After Sampling
Resample costs apply. Production schedule pushed back. Critical path impact for seasonal or time-sensitive orders.
Want to understand the full production timeline?
Learn about MOQ, lead times, and sampling cycles in our dedicated guide.
Recommended Reading
Continue building your packaging knowledge with these related guides from our Resource Hub. Each guide is designed to support a specific stage of your packaging project.
Artwork, Dielines & Print Files Guide — the complete technical preparation guide you're reading now.
Understand gusset types, bottom structures, handle options, and how structural decisions affect your dieline layout.
Dive deeper into paper substrates, lamination types, printing methods, and how material choice affects color output.
Learn how correct file preparation connects to production QC — and how we inspect printed output against your approved samples.
More Resources from Our Hub:
Frequently Asked Questions
Real questions from packaging buyers at every stage of the sourcing process. If you don't see your question here, contact our prepress team directly.
Yes. Send us your desired internal dimensions (L × W × H, and gusset depth for bags) and we will provide a production-ready dieline in .AI or .PDF format — at no charge. We support all our standard product categories including paper bags, paper boxes, greeting cards, and tags.
We prefer Adobe Illustrator (.AI) or high-resolution PDF (PDF/X-4 preferred). All text must be converted to outlines and all images embedded within the file. Do not send Canva exports, Word documents, or JPEG files as primary artwork.
Standard bleed is 3–5 mm beyond the cut line on all sides. Keep important text, logos, and design elements at least 5 mm inside the cut line (safe zone). For very large packaging (e.g., large shopping bags), consider 5 mm bleed to account for production variance.
Use Pantone when exact brand color consistency is critical — especially for logo colors, brand standards, and repeat orders where color must match across print runs. CMYK is sufficient for most full-color artwork. If unsure, request a physical sample before approving mass production.
Create a separate layer in Illustrator named exactly "Foil". Use 100% black (K: 100, C: 0, M: 0, Y: 0) vector shapes only — no raster images, no gradients. Minimum recommended stroke width is 0.3 pt. Keep foil elements at least 3 mm away from any fold or crease line. Our team will confirm placement and thickness before production.
Yes. We offer a free prepress check on all submitted artwork. Our team reviews for resolution, color mode, bleed, safe zone, outlined fonts, and layer setup. You'll receive a detailed feedback report within 1–2 business days. We recommend submitting files for review before committing to a sample order.