Print-Ready Artwork for Custom Packaging: The Complete UK Guide

Why Artwork Preparation Determines Your Entire Order Timeline

Ask any UK packaging supplier about the single biggest cause of production delays and the answer is the same every time: customer artwork that is not print-ready. Industry data collected by UK trade printers shows that roughly 35 percent of first-submission artwork files are rejected at the pre-press stage. Each rejection adds 2 to 4 working days to your timeline and, in many cases, additional artwork revision charges of £35 to £75 per round. For a cafe owner waiting on branded cups for a launch event, that delay is often more painful than the cost.

Getting your artwork right before you submit saves time, saves money, and ensures the printed result matches what you see on screen. Here is what you need to know, in the order that matters.

File Format: What Your Printer Actually Needs

The universal standard for commercial print is PDF/X-1a or PDF/X-4. These are ISO-standardised PDF variants designed specifically for print production. They embed all fonts, include colour profiles, and eliminate the most common sources of printing errors.

Acronyms you will encounter and what they mean:

• PDF/X-1a: All colours must be converted to CMYK. RGB images and Pantone spot colours are not permitted. This is the safest format and is accepted by every UK packaging printer.
• PDF/X-4: Allows both CMYK and spot colours plus transparency effects. More flexible but requires a printer who understands colour management.
• AI (Adobe Illustrator): Native Illustrator files are acceptable from most UK printers but always confirm the version. Save as Illustrator CS6 or later with fonts outlined.
• EPS: Legacy format. Still accepted but offers no advantage over PDF/X for modern print workflows. Avoid unless specifically requested.
• PSD (Adobe Photoshop): Acceptable only at 300 DPI at actual print size, with all text layers rasterised or fonts outlined. Not ideal for packaging with text.

What is never acceptable: JPEG, PNG, GIF, or any web-optimised format. Canva exports, Microsoft Word documents, and phone screenshots are also not print-ready. If your current artwork exists only in these formats, you need professional design support. We offer that at our design service.

Resolution: 300 DPI at Actual Size — Not a Suggestion

Commercial flexographic and offset printing on paper cups requires 300 DPI (dots per inch) at actual print size. This is the minimum resolution for sharp text and clean edges. Files at 72 DPI — the standard screen resolution — will print blurred and pixelated, regardless of how they look on your monitor.

What this means in practice:

• A typical 8oz cup print area is approximately 220mm wide by 85mm tall (the side wall, not including the bottom margin). At 300 DPI, your artwork file should be at least 2,600 pixels wide by 1,000 pixels tall.
• Logos pulled from your website are almost never 300 DPI at actual size. A logo that appears sharp on a 300px-wide website header will look soft when stretched across a 220mm cup at 300 DPI.
• Vector files (.ai, .eps, .svg) have no resolution limit — they can be scaled to any size without quality loss. Wherever possible, use vector artwork for logos and text elements.

Bleed: The 3mm That Separates a Clean Print From a Disaster

Bleed is the extra area of artwork that extends beyond the trim line. It accounts for the tiny variations in cutting position that occur at production speed. Without bleed, any slight misalignment in cutting leaves a thin white sliver at the edge of your print — immediately visible and immediately wrong.

Standard bleed requirement for packaging: 3mm on all sides. For bags with folds or gussets, add 5mm bleed at fold lines. This means if your final trim size is 220mm wide, your artwork file should be 226mm wide (3mm bleed on each side).

Related to bleed is the safe zone — the area inside the trim line where you must keep all critical content (text, logos, key design elements). Standard safe zone: 5mm from all edges, or 8mm for bags with complex folds. Text placed closer than 5mm to the trim line risks being partially cut off.

A practical check: imagine a pair of scissors cutting 1mm to the left of where you expect the cut to land. Is your logo still intact? Is the text still readable? If the answer is no, your safe zone is inadequate.

Colour: CMYK and the Pantone Question

CMYK (Cyan, Magenta, Yellow, Key/Black) is the standard colour model for commercial printing. Your artwork must be in CMYK, not RGB. Colours defined in RGB will be converted to the nearest CMYK equivalent, and the result is often noticeably different — blues tend to darken, bright greens flatten, and neon colours lose their punch entirely.

Pantone spot colours are pre-mixed inks that produce a precise, consistent colour. They are the gold standard for brand colours that must match exactly. Pantone colours are specified by number — for example, Pantone 185 C is a specific bright red used by many UK brands. Using a Pantone colour adds roughly 10 to 15 percent to the plate cost because each spot colour requires a separate printing plate, but it guarantees colour consistency across print runs.

A common mistake: designing in RGB on a bright, uncalibrated laptop screen, converting to CMYK at export, and being surprised that the printed result looks darker and less vibrant than expected. This phenomenon has a name: the CMYK gamut limitation. In simple terms, CMYK inks cannot reproduce certain bright colours that RGB screens can display. If brand colour accuracy matters to you — and it should — invest in a Pantone colour bridge book. These physical swatches show exactly what each Pantone colour looks like when printed in CMYK, removing the guesswork.

Fonts: Outline Everything

Convert all text to outlines before submitting your artwork. In Adobe Illustrator: Select All > Type > Create Outlines. In Photoshop: Layer > Type > Convert to Shape. Outlined text becomes a vector shape — it can no longer be edited as text, but it also cannot be substituted, corrupted, or reflowed by the printer's pre-press system.

Unconverted fonts are the single most common cause of pre-press rejection. When the printer opens your file and does not have your exact font installed, their system substitutes a default font. Your carefully chosen typeface becomes Arial or Myriad. By the time anyone notices, the plates may already be made.

If you use a custom or licensed font, confirm that your licence permits embedding in print files. Most commercial font licences do, but check.

Image Formats and Transparency

Photographic elements should be embedded, not linked. Linked images are common in professional design files — they keep file sizes small by referencing an image on disk rather than embedding it. But when the printer opens your file without access to the linked file path, the image is missing. The print operator sees a low-resolution preview or a blank box. Always embed all images before export.

Transparency effects (drop shadows, opacity gradients, blend modes) must be flattened. These effects can render unpredictably when processed through a raster image processor (RIP) — the software that converts your design file into the dots that printing plates produce. Flattening removes the transparency and bakes in the visual result. In Illustrator: Object > Flatten Transparency.

The Proofing Stage: Do Not Skip This

Every UK packaging printer offers either a digital proof or a physical proof before production begins.

Digital proofs are PDF files showing the layout, trim marks, and colour simulation. They are emailed to you and you approve them with a click. Digital proofs are fast — same-day turnaround is standard — and they confirm that the layout and text are correct. They do not accurately represent physical colour.

Physical proofs are actual printed samples of your artwork on the intended substrate. They show exactly what the ink will look like on paper, not a simulation. Physical proofs typically cost £25 to £50 and add 2 to 3 working days to the timeline. For a first-time order or a new design, a physical proof is worth the time and cost. The £50 you spend on a proof is trivial compared with receiving 5,000 cups with a colour you did not expect.

When reviewing any proof, check:

• Spelling on all text, not just the logo (ingredients, addresses, social handles — people skip these and regret it)
• Trim marks and bleed are present
• Colour appears as expected (for digital proofs, cross-reference against Pantone swatches, not screen display)
• Barcodes or QR codes scan successfully (print the proof, test with a phone)
• Phone numbers, web addresses, and social handles are current

Common Mistakes and How to Avoid Them

Based on UK packaging pre-press data, the top 5 artwork rejection reasons:

A further 10 percent of files are rejected for miscellaneous issues: incorrect page size, missing crop marks, corrupt file data, or wrong file format entirely.

Artwork for Different Packaging Types

Different products impose different artwork constraints:

Paper cups. The print area is the side wall — a curved rectangle. Artwork reads around the cup. Avoid placing critical information near the cup seam (bottom join) where distortion is highest. The bottom of the cup is not typically printed. Rim diameter and taper angle affect the print template, so always request the dieline from your supplier before laying out artwork.

Takeaway boxes and food containers. Flat-pack boxes are printed on the flat sheet before die-cutting and folding. The dieline shows the fold lines, glue flaps, and print-safe areas. Artwork on glue flaps will be concealed after assembly. Text placed across a fold line will be partially visible on two different panels — sometimes this is intentional, usually it is a mistake.

Paper bags. The print area includes the front panel and often the side gussets. Handle areas and the bag mouth are typically unprinted. If you want a full-bleed design that wraps around the gussets, confirm this with your supplier before designing — it requires specific layout planning.

For more detailed guidance on bag artwork, read our custom paper bag artwork checklist.

What If You Do Not Have a Designer?

Many small UK operators do not have an in-house designer or an agency relationship. This is common and it is not a barrier to getting custom-printed packaging. Your options:

Use the supplier's design service. At OkeyPackaging, our free design service takes your logo, brand colours, and any reference images you have, and produces print-ready artwork to specification. You review and approve the proof before anything goes to production. This service is included with your order.

Hire a freelance packaging designer. Platforms like Behance and Dribbble list UK-based packaging designers. Expect to pay £150 to £400 for a simple cup design and £300 to £800 for a full set of packaging artwork across multiple products. Ensure the designer has packaging experience — many talented graphic designers have never worked with dielines, bleeds, or flexographic colour profiles.

Learn the basics. If you are comfortable with Adobe Illustrator, invest 2 to 3 hours in learning the packaging-specific settings: document setup with bleed, CMYK colour mode, and outline fonts. There are excellent free tutorials on YouTube covering packaging artwork preparation.

Timeline Expectations

A realistic artwork preparation timeline for a new custom packaging order:

• Initial artwork creation: 3 to 5 working days (if you have a logo and brand assets ready)
• Design service review and first proof: 2 to 3 working days (at OkeyPackaging, often faster)
• Your review and approval: 1 to 3 working days
• Revisions if needed: 2 to 4 working days per round
• Final approval to production start: 1 working day

Total from starting artwork to production-ready files: typically 7 to 14 working days. Rush service is available from some suppliers — OkeyPackaging can turn around artwork in 48 hours for urgent orders — but rushing artwork is best avoided. Mistakes happen when people hurry.

Checklist Before You Press Send

Run through this checklist before submitting artwork to any UK packaging printer:

1. File format is PDF/X-1a or PDF/X-4, or native AI with fonts outlined
2. Resolution is 300 DPI minimum at actual print size; logos are vector
3. Colour mode is CMYK; Pantone references are specified if used
4. 3mm bleed is present on all sides; backgrounds extend fully into the bleed area
5. All text is at least 5mm inside the trim line (safe zone)
6. All fonts are converted to outlines
7. All images are embedded, not linked
8. Transparency effects are flattened
9. Document size matches the supplier's dieline exactly
10. You have checked spelling on every word, including web addresses and phone numbers

If you tick all ten boxes, your file will pass pre-press on the first submission. If you are unsure about any point, ask your supplier before submitting. We would rather spend ten minutes answering a question than three days reworking a file that should never have been sent.

For help with artwork preparation or to use our free design service, visit the OkeyPackaging design page or request a quote with your specifications.