Engraved text and logos on prototypes.
A perfectly legible logo in CAD can lose definition after sandblasting, anodizing, or painting. The result depends on the size, stroke, depth, material, and finish.
Including text, a reference, a serial number, or a logo in a part or prototype may seem like a simple design detail. However, when that information must be manufactured via CNC machining, 3D printing, or engraving, the final result depends on several factors: size, stroke thickness, depth, geometry, material, and surface finish.
Text that is too small can be difficult to machine or end up being unreadable once the part is manufactured. Designing text and logos correctly allows you to avoid rework and ensure that identification, branding, or technical information remain visible on the final product.
What is the difference between engraved text and raised text?
Before defining dimensions, it is advisable to decide how the text will be integrated into the part.
Common in machined parts, plates, industrial components, housings, or parts requiring permanent references.
It can work well on 3D printed parts or plastic elements, although it remains more exposed to impacts, wear, or subsequent processes.
From a manufacturing perspective, both solutions require controlling the minimum size of details and ensuring that the selected technology can reproduce them.
Minimum text size: there is no universal measurement
One of the common questions is what the minimum size for engraving text on a part is. There is no single answer. Readability depends on:
- The manufacturing technology.
- The material.
- The tool diameter in CNC machining.
- The resolution of 3D printing.
- The depth or height of the engraving.
- The font type.
- The subsequent surface finish.
- The distance from which it will be read.
As a design guideline, the smaller the text, the more important it is to use simple and sufficiently thick strokes. A 2 mm high font with very thin lines may be less readable than a slightly larger one with a more open geometry.
When space is available, moderately oversizing the text is usually safer than working near the technological limits of the process.
Choose appropriate fonts for CNC machining and 3D printing
Typography directly influences manufacturing ease. For CNC-engraved text, simple fonts without serifs and with uniform strokes usually work best. Excessively decorative typefaces may include small curves, narrow spaces, or details impossible to reproduce with a specific tool.
Sans serif fonts are usually a more robust option for industrial applications. It is also advisable to review these letters especially:
In 3D printing, excessively fine details should also be avoided, as they may lose definition depending on the orientation, resolution, and process used.
Stroke thickness: just as important as height
Increasing letter height is not enough. The minimum stroke thickness is one of the parameters that most affects readability. A large letter drawn with extremely fine lines may disappear during machining or remain poorly defined after finishing.
In CNC machining, the internal radius of the letters will also be conditioned by the tool diameter. If the design includes excessively small internal corners, the final geometry must be adapted to the end mill radius.
Think of the text as a manufacturable geometry, not just as a graphic element.
Engraving depth: deeper is not always better
The depth of the CNC engraving must be sufficient for the text to remain visible after the finish, but it does not necessarily need to be very deep. An excessively deep engraving can:
- Increase machining time.
- Create hard-to-clean areas.
- Generate paint or dirt accumulations.
- Weaken very thin walls.
- Make a small detail appear visually too aggressive.
Conversely, an overly shallow engraving may lose contrast after sanding, polishing, anodizing, or painting. Therefore, the depth must be defined considering both the manufacturing process and the final part finish.
How finishes affect engraved text
One of the most common mistakes is designing the engraving thinking only about the freshly manufactured part. Subsequent processes such as sandblasting, polishing, painting, anodizing, or surface coatings can slightly modify the edges and reduce the definition of small details.
It can partially fill shallow engravings.
It can smooth the letter edges.
It can reduce the contrast of very thin letters.
If the text must remain perfectly legible, it is advisable to consider the intended finish from the outset. A common strategy is to slightly increase the size, stroke thickness, or depth compared to a design that will not receive any subsequent treatment.
Logos: simplifying can improve the result
Logos usually present an additional challenge because they may contain very small details that were not designed with manufacturing in mind. Before machining or printing a logo, it may be necessary to:
- Remove elements that are too small.
- Increase the spacing between lines.
- Simplify curves.
- Thicken specific strokes.
- Create a specific monochrome version for manufacturing.
It is not always necessary to reproduce the original graphic file with absolute fidelity. In many applications, an optimized version maintains the visual identity and offers a much cleaner result.
Engraved text or post-process marking: what to choose
Not all text needs to be part of the part geometry. For variable identifications, serial numbers, or codes, it may be more efficient to resort subsequently to technologies such as laser marking.
Conversely, when the information must remain physically integrated in the part, machined or printed engraving offers a permanent and robust solution. The choice will depend on the number of parts, the material, the finish, and whether the content is fixed or changes between units.
