Printing small text on 3D printed name keychains

A name keychain is small, and the name on it is smaller. When the letters come out blobby, stringy or broken, the whole product looks cheap, however good the design is. The good news is that sharp small text is mostly a matter of a few settings and a few rules about lettering.

Start with the name, not the slicer

The single biggest factor in small text quality is how much space each letter gets. A four-letter name on a keychain prints large and clean. A twelve-letter name on the same keychain shrinks until the letters are thinner than your nozzle can draw.

Keep names short on keychains. First names and nicknames work best.
Put long names on bigger products. A desk name plate or a bag tag has room for "Alexandria" or a full name.
Look at the picture before printing. In the STLmint studio, the preview shows the name at its real size on the design. If it looks cramped on screen, it will look worse in plastic.

Choose lettering that suits the size

Not all lettering styles survive being small.

Bold, rounded lettering prints well at any size. The strokes are thick and the corners are soft.
Script lettering looks beautiful at a good size, but its thin connecting strokes are the first thing to break when a name gets long.
Outline or "neon" styles, like the neon name keychain, need enough space for the outline and the gap inside it.

The name keychain offers a choice of lettering. For long names, pick the boldest one.

Nozzle and layer height

Nozzle. A standard 0.4 mm nozzle prints most name keychains well. For very fine lettering, a 0.2 mm nozzle draws thinner strokes, but prints much more slowly. Most sellers are better off keeping the 0.4 mm nozzle and choosing bolder lettering.

Layer height. Raised text is only a few layers tall. Thinner layers (0.12 to 0.16 mm) give the letters cleaner sides and more defined tops. Many slicers can use a fine layer height only for the top part of a model, which keeps the base fast.

Slicer settings that matter for small text

These are the settings worth checking. Names vary by slicer, but every slicer has them.

Wall count and line width. If thin strokes vanish in the preview, the slicer has decided they are too narrow to print. Reduce the wall line width slightly, or allow thin walls ("detect thin walls" or similar).
Outer wall speed. Slow it down. Small details need time to cool.
Minimum layer time and cooling. Small letters finish each layer quickly, so the plastic doesn't have time to set. Turn the part fan up and set a minimum layer time.
Seam position. Place it at the back or in a corner, so the seam doesn't land on a letter.
Retraction. Small letters mean lots of travel between them. Tune retraction to avoid strings between letters.
Ironing. Ironing the top of the base can look great, but turn it off for the top of the letters if it rounds their edges.

Always check the slicer preview at the text layers before printing. If a letter is missing there, it will be missing on the print.

Filament makes a difference

Dry filament strings less. Damp PLA and PETG both leave fine hairs between letters.
Matte PLA hides layer lines and looks good on small text.
Silk PLA looks luxurious but is softer and strings more; it suits large text better than tiny lettering.
PETG is tougher for keychains that live on keys, but strings more than PLA. Tune it before using it for fine text.

Two colours make small text readable

The same letters are far easier to read in a contrasting colour. White text on a dark base is the easiest win for any keychain. If you don't own an AMS, a single filament change at the first layer of the text does it. See two-colour name prints in Bambu Studio.

Finish and check

After printing:

Remove strings with a quick pass of a heat gun or lighter, held well away. Practise on a failed print first.
Check every letter against the approved name before packing.
Test the hole. A keyring loop that cracks is a worse problem than a slightly soft letter.

When to tell a buyer no

Sometimes the honest answer is that a name won't fit. Suggest a nickname, initials, or a bigger product. A buyer who gets a clear, readable keychain is happier than one who got exactly what they typed in letters they can't read.

For a full guide to starting a keychain business, see how to start selling personalised 3D printed keychains.

Common questions

What is the smallest text I can 3D print? With a 0.4 mm nozzle, aim for strokes at least as wide as the nozzle, and letters a few millimetres tall. Bold lettering helps more than any setting.

Why are some letters missing in my slicer preview? The strokes are thinner than the slicer's minimum line width. Use bolder lettering, a shorter name, or enable thin-wall detection.

Should I print text face up or face down? Raised text prints best face up, so the tops of the letters are the last, cleanest layers. Follow the orientation advice on the design page.