The ‘Polonia’ violin reconstructed from tomographic data

Polonia Project

Antonio Stradivari„Polonia" · 1685

Polonia Project is Mateusz Majkowski’s own project, devoted to technical documentation drawn from the computer tomography of the 1685 ‘Polonia’ violin by Antonio Stradivari. It brings together traditional violin building, industrial metrology and three-dimensional modelling.

Aims of the project

The aim is not to reproduce the historical instrument, but to build the most complete technical documentation possible — one that allows its construction to be analysed and the data to be used at the bench. The documentation serves informed interpretation of the model, not mechanical copying.

  1. Tomographic examination of the instrument
  2. Technical documentation, moulds and construction templates worked out from that data
  3. A new instrument built from that documentation
  4. A concert for two violins — the original Stradivari and the instrument built from the research

Why Polonia

‘Polonia’ is the only instrument in Poland attributed to Stradivari. It was made in the Amatisé period, regarded as one of the most important stages in the development of Antonio Stradivari’s workshop. It was then that the constructional and stylistic solutions gradually took shape which, in the years that followed, reached their full development in Stradivari’s golden period. The tomographic examination within the project was made possible through the cooperation of Janusz Wawrowski — the instrument’s custodian, and a leading Polish violinist who performs on ‘Polonia’ regularly.

The tomographic examination

The examination was carried out on a Nikon M2 LES industrial computer tomography system. This resolution allows the instrument’s geometry, internal structure and traces of earlier repairs to be studied without touching the historical object.

System
Nikon M2 LES
Resolution
from 0.06 mm
Method
industrial computer tomography
Examination
3 September 2025 · Kielce

Technical documentation

Industrial computer tomography (CT) is a non-invasive method that uses X-rays to build a three-dimensional model of the object examined. It allows both the external geometry and the entire internal construction of an instrument to be studied without opening or dismantling it.

Tomography makes it possible to assess plate thicknesses, the run of the arching, the placement of structural elements, the quality of earlier repairs, hidden cracks and other damage that cannot be reached without opening the instrument. Analysis of the data also allows the distribution of wood density to be determined — a valuable complement to materials research and dendrochronology.

From the data obtained come technical drawings, tomographic sections, tables of measurements, plate thickness maps, three-dimensional models, and the constructional documentation used to design moulds and bench templates.

The aim of the technical documentation is to record the geometry and construction of the instrument as faithfully as possible. It concentrates on dimensional record and structural analysis; it does not serve to establish authenticity or attribution.

From the industrial computer tomography data, and in collaboration with Bartłomiej Czapla, a complete set of technical documentation for the ‘Polonia’ model was worked out: technical drawings, digital models of the instrument’s geometry, sections through the arching, and the set of outline templates needed to build a new instrument.

From that documentation came a full set of bench templates, laser-cut from 1 mm stainless steel, and a three-part construction mould in HPL laminate — the basic equipment used while building the instrument. Every element was derived directly from the tomographic data, keeping one common reference geometry.

  • Industrial computer tomography
  • Three-dimensional and volumetric models
  • Tomographic sections
  • Technical drawings
  • Tables of measurements
  • Plate thickness maps
  • Construction moulds
  • Workshop templates
  • 3D-printed reference models
  • The complete set in its transport case — templates, mould and scroll model in foam inserts

    The complete set in its transport case — templates, mould and scroll model in foam inserts

  • The set laid out: four inserts holding the complete contents

    The set laid out: four inserts holding the complete contents

  • The construction mould with the outline template and assembly screws

    The construction mould with the outline template and assembly screws

  • Arching and outline templates, laser-cut from stainless steel

    Arching and outline templates, laser-cut from stainless steel

  • Reference model of the scroll — the ‘Polonia’ Stradivari

    Reference model of the scroll — the ‘Polonia’ Stradivari

The model from tomography

An STL surface model derived from the industrial computer tomography data. It preserves the instrument’s geometry and is the basis for measurement, analysis and the preparation of technical documentation.

Three-dimensional model

Computer tomography · 2.5M triangles · 0.55 mm edge

Left button rotates · right button pans · wheel zooms · slider cuts

Physical 3D models

The reference 3D models are made directly from the industrial computer tomography data of the instrument. They are printed in light-cured photopolymer resins at a layer height of 0.02 mm, then scanned again and analysed on the computer to verify that they match the original tomographic data.

They are the modern counterpart of traditional plaster casts, without their basic limitations: brittleness, dimensional instability and the inability to reproduce the internal geometry of the object. The material is highly stable dimensionally, so the models can serve as lasting reference masters in research and at the bench.

High scanning resolution combined with the precision of 3D printing reproduces the instrument’s geometry faithfully — down to the tool marks left when the scroll was carved by hand.

Every model comes with printed technical documentation giving the basic dimensions and technical drawings.

Every scroll model is made to individual order.

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Object
reference model of the scroll
Source
Nikon M2 LES computer tomography data
Made by
3D printing, photopolymer resin, 0.02 mm layer
Colour
beige

Model quote

A request for a quote — this is not a binding order. We reply to the address given, with a price, a lead time and the cost of shipping.

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  • The scroll of the ‘Polonia’ violin by Antonio Stradivari

    The scroll of the ‘Polonia’ violin by Antonio Stradivari

  • The lion’s head from an instrument by Marcin Groblicz

    The lion’s head from an instrument by Marcin Groblicz

Building the instrument

An integral part of the project was building a new instrument on the ‘Polonia’ model. It is not a faithful copy of the historical instrument but a present-day interpretation of its geometry, based on analysis of the tomographic data and on the technical documentation prepared from it. The resulting instrument is a practical test of the documentation method and of what it allows in contemporary violin building.

Building the instrument was also made possible by the support of trade partners. Old Wood, Pirastro and Despiau supplied components used during the work — varnish materials, strings and bridges — a substantial part of the project’s realisation.

The project is planned to close with a concert for two violins, in which the original ‘Polonia’ and the instrument built from the technical documentation will be heard together.

View the instrument
Violin on the ‘Polonia’ model
Violin on the ‘Polonia’ model · 2026

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