Understanding Marburg Medium: The Standard Typeface for Pharmaceutical Braille

Marburg Medium is the cornerstone of pharmaceutical Braille specification worldwide. Developed to deliver consistent tactile readability across languages, substrates and production methods, it defines the spatial geometry that makes compliant Braille possible. Yet despite its importance, brand teams and artwork agencies still encounter quality issues caused by substituting non-standard fonts or mis-managing Braille assets during artwork creation.

How Marburg Medium Standardises Braille Geometry

The Marburg Medium spacing convention sets out the precise horizontal and vertical distances between Braille dots, letters and words. ISO 17351 recommends its use for medicinal packaging, defining it as the reference spacing system for pharmaceutical Braille (see definition of “Marburg Medium spacing convention” in ISO 17351, Terms and Definitions).

The specification fixes critical dimensions such as:

• Dot diameter (1.6 mm)
• Horizontal spacing between dot centres (2.5 mm)
• Vertical spacing between dot centres (2.5 mm)
• Letter spacing (6.0 mm)
• Word spacing (12.0 mm)

These values form the geometric backbone of pharmaceutical Braille and ensure that embossing dies, screen-printed dots and inkjet systems all produce equivalent tactile results. Annex B of ISO 17351 illustrates these values and highlights the tolerances permitted in packaging production  .

PharmaBraille font families—including the Marburg-aligned country-specific sets—are built precisely to these measurements. When set at 10 mm size with 10 mm leading, they generate artwork that conforms to the spacing and size requirements.

Why Font Substitution Undermines Compliance

Using desktop or visually similar Braille fonts is one of the most common causes of regulatory non-conformance. Unlike print typefaces, Braille fonts encode geometry, not aesthetics. Any deviation in dot size, spacing or alignment results in one of three risks:

1. Reduced tactile legibility, especially on more variable substrates such as recycled board.
2. Production inconsistency, where embossing tools derive from incorrect digital geometry.
3. Regulatory non-compliance, as the resulting Braille may fall outside ISO 17351 spacing or height expectations.

ISO 17351 further reminds stakeholders that the Marketing Authorisation Holder (MAH) must specify the correct spacing convention and character set for each market, and that Braille must not compromise printed text legibility  .

Artwork errors often arise from mishandled digital assets, such as outline conversions, accidental reflow, or the use of unlicensed or corrupted font files. Because Braille characters are based on fixed dot matrices, even tiny distortions introduced during PDF generation or pre-press processing can cascade into tooling errors.

Correct Digital File Handling and Licensing

To safeguard accuracy and tooling precision:

• Always use licensed PharmaBraille fonts for each language market.
• Do not substitute system Braille fonts or online downloads.
• Maintain separate Braille layers in artwork, as recommended by ISO 17351 Annex D, to prevent accidental modification and simplify quality checks.
• Verify all Braille character sets against the intended market; national deviations exist, and ISO 17351 confirms that character sets differ between territories (Annex B and Annex E).

Best Practices for Artwork Setup and Verification

A robust internal workflow prevents most Braille-related deviations. Recommended practices include:

1. Artwork Setup

• Set PharmaBraille fonts at 10 mm size and 10 mm leading, ensuring no added tracking or spacing adjustments.
• Left-align Braille text to avoid unintended justification changes.
• Keep Braille on its own dedicated layer and avoid using the same colour for any other artwork elements .
• Confirm that the correct language-specific font is used—especially for markets with accented letters, dual alphabets or diacritics.

2. Production Alignment

• Supply packaging partners with the exact approved digital file, not screenshots or extracted vectors.
• Ensure die-makers and embossing suppliers confirm scales at 1:1, using the original Marburg-aligned digital geometry.
• Where possible, send a hardcopy proof showing Braille on a separate page, as recommended in ISO 17351 Annex D.

3. Verification and Sign-Off

• Check Braille translation and character sets at every artwork iteration.
• Confirm toolmaker proofs against the Braille master file.
• For critical markets, conduct random tactile checks during print runs in line with ISO 17351’s recommended controls for MAH incoming inspection (Annex C.6).

4. Cross-Department Communication

• Ensure Regulatory, QA, Artwork and Packaging teams share a unified Braille specification document per SKU.
• Maintain a controlled repository of approved Braille text and font assets.
• Require external design agencies to evidence use of the PharmaBraille font files.

References

• ISO 17351:2013 — Packaging — Braille on packaging for medicinal products 
• Marburg Medium spacing convention (blista)
• PharmaBraille Font System — Font specification and usage guidelines 
• EMA — Guideline on the Readability of the Labelling and Package Leaflet