Designing a custom mailer box requires both creativity and precision. The fun part is your brand story; the critical part is preparing a print-ready file that produces crisp graphics, accurate color, and tidy edges once it’s cut and folded. This step-by-step guide walks you through Box Genie’s custom mailer box artwork guidelines so your first pass prints beautifully.
You can also refer to our Packaging Design Guidelines.
1. Start with the Correct Dieline
Create a dieline for your exact mailer size and style. Place that dieline as your top reference layer and lock it. On Box Genie dielines, blue lines indicate cuts and red lines indicate folds. Build your artwork on layers beneath the dieline so you never accidentally edit it.
Safe areas matter: Keep all logos, text, and critical art at least 1/8 in (0.125") away from blue cut lines and at least 1/8 in (0.125") away from red fold lines. Paper can shift slightly during production; this buffer prevents trims from nicking artwork and keeps type off creases.
2. Set Up Your Document the Right Way
Create your working file at the exact dieline dimensions. Use CMYK color mode from the start — Box Genie’s digital presses print in CMYK. If you build in RGB, your colors will be converted at output, which can alter the appearance.
- Resolution: Place raster artwork at 100% scale with a minimum of 300 DPI. Upscaling low-res images after the fact won’t restore detail and often results in soft or pixelated prints.
- Bleeds: Extend backgrounds, patterns, and artwork that should run to the edge past the cut line (bleed) so no hairline gaps appear after trimming. Your dieline will indicate the bleed boundary — extend artwork to that boundary everywhere you expect edge-to-edge coverage.
3. Choose a Supported File Workflow
Box Genie accepts working files in .ai, .eps, or .pdf. Once you’re done, upload the final PDF of the template to boxgenie.com.
- Designing offline: Follow the step-by-step in the Designing Your Packaging Offline guide, then export a press-ready PDF from Illustrator or your preferred vector tool.
- Using the online 3D Design Tool: Upload PNG or JPEG images only (that tool doesn’t accept vector formats). For transparency, use PNG; for photos, high-quality JPEGs are fine. Keep those image assets at 300 DPI at their final size.
4. Build Clean, Production-Ready Layers
Keep your dieline on its own locked layer. Place background fills/patterns on a separate “Background” layer, then create additional layers for graphics and type. This separation makes preflight checks faster and reduces the chance you’ll accidentally move the dieline or hide important art beneath it.
5. Best Practices for Text and Graphics
Choose clean, legible fonts and reserve decorative faces for short headlines. Convert type to outlines before exporting your final PDF to prevent font substitution. Keep an eye on contrast (light type on light backgrounds and dark type on dark backgrounds can disappear when printed on textured substrates).
- Sizing your text: Body copy on corrugated or kraft-tone surfaces benefits from a bit more size and weight than it would on coated paper. If it’s critical information, such as addresses, ingredients, or care instructions, it’s better to size up rather than down.
- Vector first: Whenever possible, use vector logos, icons, and illustrations. Vectors remain sharp on both tiny flaps and large panel areas.
- Line work: Use sensible stroke weights so fine details don’t break up on press. If a line looks wispy on screen when you zoom out, it might be better to thicken it slightly.
- Avoid text near folds: Avoid placing small copy on or near red fold lines; even with the safe area, folded surfaces can curve light and make tiny type hard to read.
6. Image and Graphic Quality Checks
Before you fall in love with a layout, zoom to 100% and inspect all placed images:
- Are they 300 DPI at the size they’ll print?
- Do they span a fold or a tuck? If so, will the visual still make sense when broken across panels?
- Is there enough contrast between the image and the overlaid text or codes?
7. Color Management for Reliable Results
Everything you hand off should be CMYK. If you begin in RGB (common for photos and screen design), convert early and adjust in CMYK so you can see what will actually print. Rich, neon-leaning RGB colors often become muted when converted; better to tweak your palette yourself than be surprised later.
Expect slight shifts between screens and print. Monitor calibration, paper tone (white vs. kraft), and lighting all influence perception. Avoid over-saturating backgrounds; extremely dense builds can muddy fine details.
8. UPC and QR Codes that Scan the First Time
Barcodes and QR codes deserve their own checklist:
- Placement: Put them on a flat panel, away from folds and cuts—ideally outside that 1/8 in safe area.
- Size & resolution: Place at 100% scale with 300 DPI. Do not stretch or warp.
- Quiet zone: Leave a clear margin around the code (no patterns or text crowding the edges) to improve scan reliability.
- Contrast: Dark code on a light, even background is best. Avoid gradients or photo textures behind codes.
You can print a test on a desktop printer at actual size, then scan with a few different phones or scanners. If it reads there, you’re in good shape for production.
Bring your design to life with Box Genie. From first draft to finished box, we’ve got you covered. Design online to experiment with color, patterns, and placement on a live 3D model, or download the dieline to perfect typography and vectors offline. Choose your workflow and get started!