4B EngraverHow to add a logo to an STL file without CAD
You do not need CAD to put a logo on an STL. Upload the model and a high-contrast image to the 4B Engraver, pick the face you want, and it traces the dark areas of the image and cuts them into that face as a recess, then returns a watertight 3MF and STL. Generation takes roughly 3 to 10 seconds per part.
It works without modelling because an engraved logo is a subtraction from existing geometry, not a redesign. Three decisions actually matter: which face, how deep, and whether the thinnest line in your artwork survives a 0.4 mm nozzle.
What kind of model can I engrave?
The requirements are narrow, because they are what a clean flat recess needs:
- A single object, not several separate bodies saved into one file.
- A flat top or bottom face to cut into.
- STL or 3MF, up to 80 MB.
There is also a wall check. Before cutting, the tool measures the material left directly under the engraved shape, using a 0.3 mm halo around the actual glyphs rather than the bounding box, and refuses any depth that would leave less than depth plus 0.8 mm of wall. The two built-in cable winders have room to spare: 16.4 mm under the logo area on the 1 m USB-C-to-USB-C winder, about 39 mm on the MagSafe spooler. A thin lid sits far closer to the limit, and there the check decides your depth for you.
What makes a good logo image?
Dark areas become the recess, light areas stay at the original surface, so the ideal source is a flat black mark on a white or transparent background. PNG, JPG and WebP all upload. If your artwork is light on dark, switch on the invert option and the white shape becomes the recess instead. Gradients, soft shadows and photographic logos trace badly, because mid greys are ambiguous.
How should I prepare the image before uploading?
- Trim the whitespace. Empty margin scales along with the mark, so artwork with a wide border lands smaller on the part than it needed to.
- Kill the hairlines. Work out what a thin line becomes once the logo is scaled to fit the face. Under 0.8 mm it will not print as a groove.
- Prefer solid shapes. A filled silhouette holds up at this size; the same mark drawn as a thin outline does not.
- Take the tagline out of the image. Add a name or a serial as text rather than pixels, so the strokes can be measured and thickened if needed.
Where does the logo go, and what fits alongside it?
One face is the logo face: your logo, optionally with a serial number underneath. The other is the personal face, and takes exactly one of a name, a serial number or a logo. Use both. Crowding logo, name and serial onto one small face drops the text to about 3.0 mm cap height with 0.85 mm strokes, not far above the 2.5 mm at which the tool warns you, and splitting them is what buys the size back. Prefixes and batch runs are covered in serial numbers.
Orientation then does the rest, for text rather than the logo. A seven-letter name set upright on the small winder's oval face reaches 4.4 mm cap height; on Auto, rotated along the longest clear strip beside the connector pocket, the same name reaches 8.3 mm with 1.7 mm strokes. Same part, nearly double the letter. Logos are never rotated arbitrarily, so a logo has to fit its face as drawn.
How deep should the logo be cut?
Leave it at 1.2 mm unless the wall behind it is thin. That is 10 layers at a 0.12 mm layer height, and the selectable range is 0.6 to 2.0 mm: 0.6 mm is 5 layers and the practical minimum for a clean recess, while past about 2 mm the extra depth rarely adds legibility and eats wall thickness. Depth also fixes the layer at which a filament swap would fill the logo in a second colour, which engraving depth goes into.
| What | Measured value |
|---|---|
| Minimum usable recessed stroke, 0.4 mm nozzle | 0.8 mm |
| Automatic letter thickening, up to | 0.22 mm |
| Default depth | 1.2 mm (10 layers at 0.12 mm) |
| Selectable depth range | 0.6 to 2.0 mm |
| Wall kept under the recess | depth + 0.8 mm |
| Material under the logo, 1 m USB-C-to-USB-C winder | 16.4 mm |
| Material under the logo, MagSafe spooler | about 39 mm |
| Upload limit and generation time | 80 MB, 3 to 10 s per part |
How do I check it before printing?
Every output is verified watertight, and each engraved floor is verified to exist at the requested depth, with floor area at least 80% of the intended shape area. That catches geometry failures, not design mistakes, so use the live 3D preview and the flat face maps for the rest. Rotate to the top and bottom views and look for islands that have vanished: counters inside letters, dots, small enclosed shapes. Check that the logo sits where you expect and does not run into a pocket or a fillet.
Should I print the 3MF or the STL?
You get both for every part, so the decision can wait until you are at the slicer. Print the 3MF when the model arrived with a print profile or paint-on supports worth keeping: the 3MF carries both, and the engraver transfers the painted data onto the surviving triangles by centroid matching after the cut. Take the STL when you are mixing several different parts on one plate, or your slicer is not Bambu Studio; it carries geometry alone. 3MF vs STL weighs the two properly. Either way, download both within 7 days: the server deletes them after that.
Try it on your own model. Upload an STL or 3MF, add a logo, a name or a serial number, and download a print-ready file.
Open the engraver — freeFrequently asked questions
Can I add a logo to any STL file?
It needs to be a single object with a flat top or bottom face, up to 80 MB. The tool also measures the material directly under the engraved shape and refuses any depth that would leave less than depth plus 0.8 mm of wall, so very thin lids and shell walls may be rejected at 1.2 mm but accepted at 0.6 mm.
What image format and style works best for the logo?
Upload PNG, JPG or WebP. Dark areas are traced and become the recess, so a flat black mark on a white or transparent background works best. For white-on-black artwork, switch on the invert option. Avoid gradients, soft shadows and photographs, because mid greys leave the tracer guessing whether they are material or air.
Why did the fine detail in my logo disappear on the print?
Anything narrower than 0.8 mm after scaling is below the minimum usable recessed stroke for a 0.4 mm nozzle: the slicer's perimeters merge and the groove fills in. The automatic correction measures engraved text by erosion and thickens it by up to 0.22 mm, so hairlines and thin outlines in an uploaded image are the ones to fix yourself, in the artwork, before you upload it.
How deep should a logo be engraved?
The default of 1.2 mm, which is 10 layers at a 0.12 mm layer height, suits most parts. The selectable range is 0.6 to 2.0 mm; 0.6 mm is 5 layers and the practical minimum for a clean, visible recess. Past roughly 2 mm the extra depth rarely adds legibility and eats wall thickness the part may need.
Does the tool rotate my logo to make it fit?
No. Logos are never rotated arbitrarily, so a logo has to fit its face as drawn. Text is different: Auto orientation tries rotations and keeps the largest fit, which on the small cable winder takes a seven-letter name from 4.4 mm cap height upright to 8.3 mm with 1.7 mm strokes. Upright only keeps text horizontal.
Will the engraved file keep the original model's supports and settings?
In the 3MF, yes. It carries the print profile, plate layout, filament assignment and per-triangle painted data, including paint-on supports, and the engraver transfers that painted data onto the surviving triangles by centroid matching after the cut. An early build lost it, and the unsupported bridge inside the connector pocket printed with a rough, sagging ceiling. The STL carries geometry only.