Text to STL — Turn Words into Touchable Objects
Type a word, get a 3D-printable model. Sounds simple — and it is. But the difference between a text print that looks crisp and professional versus one that looks blobby and fragile comes down to font choice, sizing, and extrusion settings. This guide covers which fonts produce the best 3D prints, how to size text for different applications, and when you should use SVG extrusion instead for truly sharp results.
Font Selection: Which Fonts Print Well
Bold Sans-Serif Fonts — The Safest Choice
Arial Bold, Helvetica Bold, Impact, and similar heavy sans-serif fonts produce the most reliable 3D prints. Their thick, uniform strokes are sturdy enough to survive printing and handling. Letters like "i" and "l" have enough mass to not snap off. For keychains, signs, and anything that will be handled, use a bold sans-serif font. The tool defaults to a bold weight for this reason.
Serif Fonts — Beautiful but Delicate
Times New Roman, Georgia, and other serif fonts have thin strokes and delicate serifs that may not print well at small sizes. Below 20mm character height, serifs can become too thin for FDM nozzles. Use serif fonts only for large prints (40mm+ character height) where the thin strokes are thick enough to print reliably. For resin printers, serif fonts work at much smaller sizes due to higher resolution.
Script and Decorative Fonts — High Risk
Cursive, handwriting, and decorative fonts often have extreme thin-to-thick stroke variation. The thin connecting strokes between letters are typically too fragile for FDM printing. For decorative fonts, use SVG extrusion instead — create your text in a design tool, convert to outlines, and use our SVG to STL converter which handles thin strokes better through path extrusion.
Sizing Guide: How Big Should Your Text Be?
| Application | Recommended Height | Notes |
|---|---|---|
| Keychains | 15-25mm | Keep to 1-3 characters. Bold fonts only. Add a hole in your slicer for the keyring. |
| Cake toppers | 40-60mm | Taller text for visibility. Print with a spike or base for mounting. Food-safe PLA required. |
| Desk nameplates | 20-35mm | Full names work at this size. Add a base plate for stability. Serif fonts acceptable here. |
| Wall signs | 50-100mm | Large text for viewing distance. Multiple pieces may be needed for long words. |
| Stamps (reversed) | 10-20mm | Use the invert toggle to create a negative impression for stamping. Small text needs resin printing. |
Text-to-STL vs SVG Text: When to Use Each
Use Text-to-STL When:
- You want instant results — type and download
- You are making simple signs, keychains, or labels
- You need short text (1-8 characters)
- You are using bold sans-serif fonts
- Precision is less critical than speed
Use SVG to STL When:
- You need pixel-perfect letter edges
- You are using decorative or serif fonts
- You need multi-line text or paragraphs
- You want exact control over kerning and spacing
- Your text is part of a larger design with graphics
Font Printability: Real-World Test Results
We tested common fonts at 20mm character height on a standard 0.4mm nozzle FDM printer. Here is what survived printing and handling.
| Font | Printability | Notes |
|---|---|---|
| Arial Bold | Excellent | The gold standard. Uniform stroke width, no thin sections. Every character prints reliably. |
| Helvetica Bold | Excellent | Nearly identical to Arial Bold. Slightly tighter letter spacing may cause merging on small prints. |
| Impact | Excellent | Very thick strokes. Best for keychains and small items. Letters are chunky and durable. |
| Arial Regular | Good | Works at 20mm+. Below 15mm, thin strokes on "i", "l", "t" may snap. Bold weight is safer. |
| Times New Roman Bold | Good | Serifs print well at 25mm+. Below 20mm, serifs become fragile nubs. Use for large display text. |
| Courier New Bold | Excellent | Monospaced, uniform width. Every character has the same footprint. Great for technical labels. |
| Georgia Bold | Good | Elegant serifs. Similar to Times New Roman. Slightly thicker serifs print better at smaller sizes. |
| Brush Script MT | Poor | Extreme thin-to-thick variation. Connecting strokes are hairline thin. Fails FDM printing. Use SVG. |
Problem Characters: Letters That Break
Some letters are structurally challenging for 3D printing regardless of font. Here is how to handle them.
Lowercase "i" and "j" — The Dot Problem
The dot above these letters is a tiny isolated island that may not adhere to the print bed. At small sizes, it can break off during handling. Solutions: (1) Use a bold font where the dot is larger. (2) Add a thin connection bridge from the dot to the stem in your design tool. (3) Print the text on its side so the dot prints as part of the continuous layer. (4) Accept that the dot may fail and glue it back on afterward.
Uppercase "A", "B", "D", "O", "P", "Q", "R" — Internal Holes
Letters with enclosed spaces (counters) create floating islands above the base plate. The slicer needs to bridge or support these areas. Solutions: (1) Print with the text face-down on the bed — the counters print as holes in the first layer. (2) Add a thin break-away support inside the counter. (3) Design the text as an outline rather than a solid extrusion. (4) For large signs, print face-up and let the slicer handle the bridging.
Lowercase "a", "e", "g" — Tiny Counters
These have very small internal spaces that may close up during printing. At 10mm character height, the hole in an "a" is about 2-3mm wide — just a few nozzle widths. Solutions: (1) Choose a font with large, open counters (Arial, not Times). (2) Increase character size. (3) Switch to SVG extrusion for better control over stroke and counter size.
Text Sizing Formula
Use this formula to estimate the minimum character height for reliable printing with a 0.4mm nozzle: Minimum height (mm) = 2.5 × (nozzle size in mm) × (stroke scale factor). Stroke scale factor: Bold fonts = 1.0, Regular fonts = 1.5, Light fonts = 2.5.
Example 1: Arial Bold with 0.4mm nozzle: 2.5 × 0.4 × 1.0 = 1.0mm minimum. But this is theoretical — in practice, 10mm is a more realistic minimum for readability. The formula gives the absolute smallest printable stroke, not the recommended size.
Example 2: Times New Roman Regular with 0.4mm nozzle: 2.5 × 0.4 × 1.5 = 1.5mm minimum. The serifs need 50% more size to print cleanly. Practical minimum: 20mm character height for good serif definition.
Resin printer note: With a 0.05mm pixel size, the minimum drops to ~0.13mm for bold fonts. This means 3mm character height is possible with resin printing — suitable for jewelry and miniature text the FDM cannot touch.
For sharp text with exact font control, SVG extrusion produces superior results.