Real handwriting.
Rendered at production scale.
The rendering engine used by direct mail houses, agencies, and print shops to ship pen-on-paper letters through their existing fulfilment stack — via our API, straight to your SFTP.
Over 50 handwriting styles with real pen physics. PDF/X-4 output with your ICC profiles. A production REST API with webhooks, immutable outputs, and SFTP / S3 delivery. Priced per page in pence — you set your customer's rate; we power the render.
Each letter renders with per-character variation, natural imperfections, and genuine ink texture. What lands in your customer's mailbox looks like a human sat down and wrote it.
See it before you sign up
Download a CMYK Inkli engine sample.
A print-ready PDF/X-4 letterhead showing real handwriting styles, colour-managed ink presets, and natural defect variation — the actual output your press would put on paper.
How It Works
Four steps to handwritten mail
Step 1
Write your message
Compose your letter — or use a template to get started.
Step 2
Choose your defects & ink
Pick handwriting imperfections and ink colour for authentic results.
Step 3
Upload your recipients
Import a CSV or connect your CRM to personalise every letter.
Step 4
Generate campaign
Print-ready PDFs for mailing houses, or print in-house — your choice.
Want extra control? Use our advanced settings — from handwriting defects to creating your own ink presets to suit your needs. Manually or using AI Ink Studio. Learn more
Output
Two ways to print
You choose — no extra cost.
Print Ready
Generate print-ready PDFs formatted for your mailing house — hand them off directly, no extra formatting needed.
Print In-House
Download your campaign and print on your own printer. Full control, same authentic handwriting.
Inkli by Penned
Bringing Penned's handwriting technology to the printed world
Inkli brings the most advanced handwritten text generation to your direct mail campaigns — at scale. Every letter is unique, personalised, and as close as possible to pen on paper. Upload your recipients, choose your ink, and generate thousands of individually handwritten letters ready for print and fulfilment.
Why Handwritten
Trust is built by hand
We bring the power of handwritten mail to the printed world with our printed handwriting technology. Authentic, personal, and available on-demand — so every letter earns attention, builds recognition, and drives action.
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Open rate
Handwritten envelopes are almost always opened — compared to 42% for standard print.
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Response rate
Recipients are seven times more likely to respond to a handwritten letter than a typed one.
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ROI
Direct mail campaigns with handwritten letters consistently outperform digital channels on return.
Technology
Pen physics mimicking across your letters
Individual Glyph Definition
Every character is uniquely generated — no two letters are ever the same.
Pen Physics Mimicking
Ink density, pressure variation, and bleed simulated per stroke for authentic results.
Handwriting Defects
Tremor, drift, and spacing irregularity make every word look genuinely human.
Wholesale for platform partners. Self-serve for one-off campaigns.
Two paths. Pick the one that matches how you'll use it.
Platform / Partner tier
For mail houses, agencies, and print shops.
Starting from 10p per letter* — talk to sales for a tailored quote based on your volume and format. You quote your customer; the margin is yours. White-labelled end-to-end.
*Based on A4, ~800 characters per letter.
- Public REST API + webhooks
- SFTP / S3 delivery targets
- PDF/X-4 with your ICC profiles
- Sub-clients + per-client rollups
- Unmetered 3-recipient proofs
- Dedicated support
Get in touch
Questions, partnerships, or just want to say hello — we'd love to hear from you.