The Digital Reference Scan: Why One Measurement Today Determines the Condition of Tomorrow

Artworks age. This applies to paintings as much as to photographs, prints, and photographic enlargements. Colors shift, surfaces change, materials react to light, temperature, and time. What rarely changes is the assumption that the original still looks the way it did when it was created.

Those who later want to reproduce, restore, or simply document a work often face the same question: What did this work look like exactly — and how can we still reliably determine that today?

The answer we have developed at recom art care is the digital reference scan.

A reference scan is more than a high-resolution digitization. It is a precise, measurable documentation of the original’s condition at the time of capture.

Using our CRUSE scanner and the portable DOM, we do not merely capture the visual appearance of the original — we measure it. A spectrophotometer records the Lab color values directly on the original, and these values are embedded in the digital file. The scanner becomes a color measuring instrument; the resulting file is not just an image, but measurable evidence.

The result is a color-true digital proof: a file that works with objective values and — when data is migrated professionally — retains its validity over the long term. It is not subject to aging caused by environmental influences.

With 90% of all originals, we achieve a color tolerance of less than ± 2% in this process. This file serves as a reliable reference for the future — for reproduction, for restoration, for scientific documentation.

Particularly with works of digital origin — photographs or prints created from a digital file — a problem arises that is frequently underestimated.

A file alone says little about what a work actually looked like when it was approved by the artist. Give the same file to three different service providers and you will receive — despite standardized processes — three different results. Repeat the experiment five years later and the deviations are even greater: machines, materials, and software have changed.

Only files that contain Lab values function as device-independent references.

This is why, for works of digital origin, we record the measurements of the printed output immediately after its initial production. A new digital version is created that documents exactly these color and contrast values. The reference file and the physical output are measurably identical — and this correspondence can still be verified decades later.

The reference scan is not only a tool for reproduction. It is equally relevant from a conservation perspective.

The resulting file serves as a practical condition documentation of the surface: it provides the basis for recording subsequent damage and changes to the original — over long periods of time, with measurable values rather than subjective assessment.

We applied this approach in a research project in cooperation with the State Academy of Fine Arts Stuttgart, Department of Conservation and Restoration of Works of Art on Paper, Archival and Library Materials. Within the project “Sustainable Framing of Large-Format Photographs,” aging tests were conducted under constant climate and light conditions — supplemented by the Oddy test for all materials used in production. The reference scan documented and evaluated the color values of the samples before and after the tests.

A reference scan always documents only the condition on the day of capture. Conclusions about the original condition of a work at the time of its creation are not possible — this is a clear limitation we name explicitly.

What is possible: from the moment of digitization onward, an objective, measurable, device-independent reference exists. For artists, for collectors, for conservators and restorers. A foundation that does not fade.

Contact us to learn more about the reference scan or to discuss a specific project.