3mm vs 6mm vs 8mm: How to Choose the Right Font Size for Leather Hot Foil Stamping
Choosing a font size for leather hot foil stamping sounds simple.
In reality? It’s one of the most common places where things quietly go wrong.
If you’ve ever stamped a logo that felt too loud, too faint, oddly unbalanced, or just… not quite right — chances are, font size was part of the problem.
With movable type letter sets now available in 3mm, 6mm, and 8mm, the question isn’t which one is better, but which one actually fits the job in front of you.
This guide is written from the bench, not from a spec sheet. It’s based on real workshop use, ongoing discussions among leatherworkers, and the kind of trial-and-error most of us only admit to on Reddit or in private messages.
Why font size matters more than people think
Hot foil stamping isn’t just “press and go”.
It’s heat, pressure, contact area, timing — all working together.
Font size directly affects:
-
how evenly heat transfers
-
how pressure spreads across the surface
-
how clean the foil edge looks after release
-
and whether the stamp feels intentional or accidental
This is why you’ll see experienced makers say things like “same machine, same foil — totally different result” when they change font size.
They’re not wrong.
What real leatherworkers keep running into (and talking about)
If you spend any time in leatherworking communities — Reddit, Facebook groups, small workshops — the same patterns show up again and again:
-
People trying to stamp small items with fonts that are simply too big
-
Others pushing very small letters and wondering why results look weak or inconsistent
-
A lot of “my setup is fine, but something feels off” conversations
One recurring point in community discussions is that larger fonts demand more stability — more even heat, better pressure control — while smaller fonts demand precision. Neither is forgiving if used in the wrong context.
And this is exactly where size choice stops being aesthetic and starts being technical.
3mm: Small, precise, and surprisingly powerful
Let’s start with the smallest option.
When 3mm actually shines
-
Pencil stamping
-
Small leather goods (cardholders, key tags, slim accessories)
-
Subtle personalisation rather than branding
3mm fonts are often misunderstood. They’re not “entry-level” or “weaker”. They’re specialised.
Because the contact area is small, heat transfer happens quickly — but only if your setup is dialled in. On pencils or compact leather items, this size feels intentional and clean. Anything larger would simply overpower the object.
That said, 3mm fonts are less forgiving. They ask for:
-
controlled temperature
-
short, consistent dwell time
-
proper testing on scrap
Do that, and they reward you with detail that feels refined rather than timid.
6mm: The quiet workhorse
If there’s a size most workshops reach for first, it’s 6mm.
Why 6mm is so widely used
-
Wallets, notebook covers, passport holders
-
Names, initials, mid-sized logos
-
Everyday leather branding
6mm sits in that sweet spot where:
-
letters are immediately readable
-
heat spreads evenly without pushing extremes
-
results feel balanced across many leather types
In community discussions, this size is often described (sometimes without even realising it) as the “default that just works”. Not because it’s boring — but because it’s adaptable.
If you’re building a consistent brand presence across different products, 6mm is usually where that consistency starts.
8mm: Bold by design, demanding by nature
8mm fonts make a statement. There’s no way around it.
Where 8mm belongs
-
Tote bags, larger panels, covers
-
Primary logos
-
Situations where branding should be seen from a distance
But here’s the part people often skip over: 8mm fonts magnify every weakness in your setup.
Uneven heat? You’ll see it.
Inconsistent pressure? Edges will tell on you.
This is why experienced makers often mention that larger fonts require:
-
stable machines
-
proper holders
-
controlled pressure rather than brute force
When everything is right, 8mm stamps look confident and intentional. When it’s not, they’re the first to betray the setup.
A practical comparison
| Font size | Visual feel | Typical use | What to watch for |
|---|---|---|---|
| 3mm | Fine, subtle | Pencils, small goods | Precision, timing |
| 6mm | Balanced | Wallets, everyday branding | Very forgiving |
| 8mm | Bold, graphic | Large items, logos | Setup stability |
What experienced makers tend to agree on
Across forums and workshops, a few patterns repeat:
-
Test every new size on scrap first — always
-
Larger fonts need better pressure control, not higher temperature
-
Smaller fonts benefit from cleaner surfaces and shorter dwell times
None of this is revolutionary. But it’s the kind of knowledge that only becomes obvious after things go slightly wrong once or twice.
So… which size should you choose?
The honest answer: most workshops don’t choose just one.
They choose:
-
3mm for precision and detail
-
6mm for consistency and everyday work
-
8mm when presence actually matters
Movable type systems make this flexibility practical — not theoretical.
Final thoughts (from the bench, not the brochure)
Font size isn’t a preference. It’s a decision that shapes how your work is read, felt, and remembered.
Choosing well doesn’t mean choosing bigger or smaller.
It means choosing appropriately.
And once you start thinking this way, your stamping results tend to level up quietly — without needing louder branding or more pressure.
About CÍ
CÍ is a curated leathercraft tool store built around real workshop needs.
Alongside in-house manufacturing, we collaborate closely with independent tool designers and specialist brands from around the world.
We offer:
-
hot foil stamping machines
-
movable type letter sets
-
pricking irons, stitching ponies, skiving machines, cutting knives, and more
-
global free shipping in most regions
-
long-term after-sales support, not just short-term sales
The Maxita hot foil stamping machines are currently available at a discounted price, and all letter sizes (3mm / 6mm / 8mm) are in active production.
If you’re building a setup meant to last — not just to test — this is a good time to look.
References
Reddit (2023) Looking for advice on hot stamping leather, r/Leathercraft. Available at: https://www.reddit.com/r/Leathercraft/ (Accessed: 2026).
Reddit (2023) Advice for hot foil stamping, r/Leatherworking. Available at: https://www.reddit.com/r/Leatherworking/ (Accessed: 2026).
Smith, J. (2021) Heat transfer principles in foil stamping. Journal of Graphic Engineering, 14(2), pp. 45–52.
