Raised and engraved text: what reads and what does not
Minimum height, stroke width, which typefaces survive a 0.4 mm nozzle, and why recessed text usually comes out better.
Putting a logo, a serial number or a name on a part costs nothing: it adds no appreciable time and no material. What does cost you is doing it badly and discovering that at 8 mm your typeface is an illegible smudge.
The three numbers that decide
| Parameter | Minimum | Recommended |
|---|---|---|
| Stroke width | 0.8 mm (two passes) | 1.2 mm or more |
| Cap height | 5 mm | 10 mm or more |
| Depth or relief | 0.4 mm (two layers) | 0.6 – 1 mm |
The number most people get wrong is stroke width. The nozzle is 0.4 mm: a 0.4 mm stroke is a single line of plastic, fragile and with rounded ends. At 0.8 mm the stroke is two lines and reads cleanly. Below 0.8 mm, do not print text — scale it up.
Engraved or raised
On a top face, raised text comes out better: each letter builds on solid material. On a vertical face it is the reverse: raised text has a small overhang at the top of every letter and comes out with stringing, while engraved text is resolved with two perimeters inwards and stays crisp.
Which typefaces survive
- A uniform-weight sans serif, bold. It works better than anything else by a distance.
- Avoid fine serifs, italics and high-contrast faces: their thin parts fall below nozzle width and vanish.
- Open up the letter spacing. On a printed part, two letters closer than 1 mm merge into a blob.
- Watch the counters of a, e and o at small sizes: they are the first thing to fill in.
If the text is the product — dimensional letters, a sign, a nameplate — none of this constrains you: at 100 mm tall any typeface works. The numbers above are for small text on a part that does something else.