Design specifications
Templates, sizes, and safe zones for print-ready mail.
Three templates covering every document format we print: A4 letters, A5 postcards, and A6 postcards. Each shows the safe zone, bleed, address position, and barcode clear zones you need to respect for clean, machine-readable output. Download the PDF, drop it over your design, you’re done.
Download a template
Three templates, one per format.
Download the PDF template, drop it into your design tool as a reference layer, and design on top. Bleed, safe zone, and address position are all marked.
A4 letter template
A4 letters (210×297mm). Template dimensions with bleed 216×303mm. Safe zone 204×291mm. Includes the correct address position, bleed, safe-zone guidance, and code string clear zone for Intelliprint production.
A5 postcard
A5 postcards (210×148.5mm, landscape). Template dimensions with bleed 216×154.5mm. Safe zone 204×142.5mm. Address panel on the right half of the card — design on the left two-thirds, address and indicia on the right. Includes barcode clear zone.
A6 postcard
A6 postcards (105×148.5mm, portrait). Template dimensions with bleed 111×154.5mm. Safe zone 99×142.5mm. Address panel on the right — design on the left, address and indicia on the right. The most cost-effective postcard size, ideal for abandoned-cart and re-engagement mailings.
Understanding the zones
Every template uses the same set of zones. Understanding what each one means saves time when you’re designing, and avoids reprints.
Design zones
Four zones on every template.
Bleed zone
The area outside the trim line. Any background colour or image that runs to the edge of your finished piece must extend into the bleed — otherwise white edges appear where the paper is cut. For letters: 3mm bleed on each side. For postcards: 3mm bleed on each side.
Safe zone
Keep text, logos, and anything you don’t want cropped inside this area. Small shifts during trimming can take off a millimetre or two at the edges — the safe zone protects content from that. For A4 letters: 204×291mm. For A5 postcards: 204×142.5mm. For A6 postcards: 99×142.5mm.
Address clear zone
Where the recipient’s address sits. On letters, this aligns with the C5 envelope window (23mm from the left edge, 43mm from the top). On postcards, it sits in the right panel alongside the indicia. Keep all other content clear of this area so the address remains machine-readable by Royal Mail.
Barcode clear zone
A reserved strip for the barcode we print alongside each piece. Barcodes ensure the right pages match the right letters (especially for multi-page mailings), and help Royal Mail sort faster. On postcards, the barcode sits below the address panel. On A4, the code string runs down the left margin.
Postcard orientation and address panel
Postcard templates are orientation-locked: A5 postcards are landscape, A6 postcards are portrait. The address panel always sits on the right-hand side of the card, and the design space fills the left. If you upload artwork in the wrong orientation, the address and indicia won’t land where Royal Mail expects them — so we’ll reject or rotate the file.
A couple of practical implications:
- The design area on an A5 postcard is about 130×142mm — the left two-thirds of the landscape card, with 3mm bleed on the outer edges.
- On A6, design area is about 60×142mm — the left portion of the portrait card. Tight, but workable for punchy headline-and-image campaigns.
- Indicia (postage mark) is pre-printed in the top-right of the address panel on every postcard. You don’t design it — keep that space clear.
The A4 code string clear zone
A4 letters include a narrow vertical strip down the left-hand margin called the code string clear zone. This area carries a machine-readable barcode string that Intelliprint uses to match the right pages with the right letters through the print pipeline.
Keep it clear. If your design runs text or imagery into this strip, it interferes with the barcode and can cause pieces to be mismatched or rejected. It’s the single most common cause of reprint requests — and the easiest to avoid by downloading the template before you start designing.
Envelope formats
C5 and C4 — the two envelopes we use.
Your A4 letters go out in one of two envelope formats. The same A4 letter template works whether the letter is folded for C5 or sent flat in C4.
C5 (229×162mm)
Standard business envelope for folded A4 letters (typically up to 6 sheets including cover). Window at 23mm from the left, 43mm from the top — matching the A4 letter template. 1st Class, 2nd Class, Signed, or Special Delivery.
C4 (324×229mm)
Larger envelope for A4 letters sent flat (no folding), or for documents with multiple sheets. Uses the same address window position, so the A4 letter template still applies. Used where presentation matters — legal correspondence, contracts, formal notices.
Design FAQ
Common questions.
Can I use the templates in Adobe or Affinity?
Yes. The templates are PDFs with layers — drop them as a reference layer into Adobe Illustrator, Photoshop, InDesign, Affinity, or Figma. Design on top, hide the template layer before export, and submit the finished artwork.
What file format should I submit?
PDF. PDF/A if you want to be particularly cautious about font substitution. We accept other common formats (DOCX, XLSX, JPG, PNG) via the dashboard upload wizard — but PDF is the most reliable for preserving fonts, colours, and exact layout.
How do I handle variable addresses across a batch?
For letters, address variation is usually handled via mail merge (one template, merged with a list of recipients). See our mail merge at scale guide for the full workflow. For postcards, the address panel is applied at print time from the data you submit alongside the artwork — so you design the creative side once and we personalise each piece.
CMYK or RGB?
Both work. CMYK is the cleaner choice for print — it’s what the press prints in, so colour shifts are minimal. If you submit RGB, we convert automatically, but colours may shift slightly (especially bright blues and greens). If colour fidelity is critical, design in CMYK from the start.
What resolution should images be?
300dpi for all photographic and image content. Vector artwork (logos, illustrations, typography) scales cleanly and doesn’t need a resolution target. If you upload a low-resolution image and we can’t print it cleanly, we’ll flag it before production.
Do you have templates for other sizes?
All three templates are published here. If you have a specialist need — oversized format, non-standard finish, custom envelope — talk to us and we’ll advise whether it’s supported and share any additional spec documents.
Ready to design
Download a template and get started.
Your first letter through the Intelliprint dashboard, from template to posted envelope, takes about 15 minutes. Download, design, upload, post.