MetroX Pro & Revo Measure
Two antique porcelain teacups: Similar but not identical
Objetcs: Antique Porcelain Tea Cups Manufacturer: Victoria (Austria) Estimated Period: Late 19th to Early 20th Century (Circa 1891–1918)
Description: These elegant tea cups feature a fine white porcelain body with a flared rim. The exterior is decorated with a naturalistic motif depicting a bird perched on reddish-brown branches, surrounded by trailing green ivy leaves. The bird is painted in soft tones of grey, blue, and brown with a reddish breast.
The interior rim is adorned with a distinct green laurel garland pattern. The top edge features a gold dentil (sawtooth) border, adding a formal touch to the design. The looped handle is also accented with gold gilding, which shows signs of antique wear consistent with age.
These antique cups were produced by Victoria Schmidt & Co. in Bohemia (Austro-Hungarian Empire) between 1891 and 1918, as indicated by the specific “Austria” mark. This dates them to the pre-WWI era, distinguishing them from later Czechoslovakian productions after the fall of the empire. The bird and ivy motif is a classic example of the high-quality naturalistic style popular during the Victorian and Edwardian periods.
These cups were crafted using plaster molds, a technique essential for achieving their delicate, uniform shape. Liquid porcelain clay (slip) was poured into a porous plaster mold, which absorbed water from the clay, allowing the cup to harden and form a shell. The handle was either cast separately and applied by hand before firing (a common method for fine detailing) or molded as a single integral piece with the body, depending on the complexity of the mold used.
Why Apply 3D Tecnologies to Antiques?
Using advanced technologies like the Revopoint MetroX Pro & Revo Measure on two late 19th-century porcelain cups might seem like an anachronism, but in reality, it is the most effective method to reveal the “invisible history” of the objects. Here are the 4 main reasons:
1. Metrology vs. The Human Eye The human eye is excellent at perceiving beauty and color, but it is deceptive when judging geometry. Two cups may appear identical on a table but differ by millimeters in curvature.
- The Advantage: 3D scanning transforms a visual sensation (“they look the same”) into irrefutable mathematical data. With a precision of the Revopoint MetroX Pro, you eliminate subjectivity and obtain a geometric “fingerprint” of each piece.
2. Reverse Engineering the Production Process Analyzing the superimposition allows you to perform inverse “industrial archaeology.”
- Mold Identification: If the deviation map shows a perfectly green body (total overlap), you have proof that both originate from the same plaster master mold.
- Isolating the Human Factor: The deviations (red/blue areas) will show you where the artisan’s hand intervened. For example, if the handles differ while the cups are identical, you have scientifically visualized the exact moment the worker applied the handle by hand (“sprigging”) 120 years ago.
3. Thermal Deformations Porcelain is a “living” material during firing: it shrinks (up to 15%) and deforms.
- Warping Analysis: The 3D comparison reveals deformations that escape the naked eye, such as a slight ovalization of the rim. Understanding how the two cups deformed differently tells you where they were positioned in the kiln (slightly different temperatures cause different shrinkage rates) or if they were fired in different batches.
4. Non-Invasive Conservation To accurately measure the curvature of a fragile cup using traditional methods, you would need to use mechanical contact calipers, risking scratches to the glaze or the gold gilding.
- Safety: The MetroX Pro’s blue laser is a non-contact technology. It allows for in-depth analysis without ever physically touching the object, preserving its integrity for the future (creating a Digital Twin).
Scanning
Using the MetroX Pro with a rotating dual-axis turntable, the teacups was scanned in Cross Lines mode using markers for tracking. The process involved two partial scans that were later merged to create the final model.
Merging two partial scans
Merged model
Final point cloud
Size
Section: Meshmixer
Section: Blender
Morphological Comparative Analysis
Verification of geometric congruency between the two Teacup
Analysis Software: Revopoint Revo Measure.
Import in Revo Measure TeaCup2 as “Reference Data” and Teacup1 as “Scan Data”.
Alignment: Perform aligmement by selecting 5 common points on both Teacup (e.g., handle tip, base, opposite rim).
Deviation Analysis
This is the core phase that addresses the question regarding geometric superimposability (overlap).
- 3D Comparison (Color Map): Activate the 3D comparison function.
- Tolerance Setting: Set a tight chromatic scale (e.g., ±1 mm).
- Reading the Map:
- Green: Deviation < 0.1 mm (Perfect overlay, confirming the use of the same mold).
- Yellow/Red: TeaCup1 is larger/external relative to Teacup2.
- Cyan/Blue: TeaCup1 is smaller/internal relative to Teacup2.
Interpretation of Results
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Deformation (Warping): If a color gradient transitioning from red to blue across the Teacupis observed (e.g., one side positive, the other negative), it indicates that one of the Teacups ovalized differently during kiln firing or may have originated during dryng or handling before firing.
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Artisanal Variability: Pay attention to the handle attachment area. A strong deviation (intense red or dark blue) in this area will confirm that the handles were applied manually and positioned with slight differences in angle or height.
Thank you for your attention
