Holy Trinity

Sample List Heiser

Thin section No.: H2

Brief description: wood sample, frame

Sampling location: from loss in frame at the left

Sample No.: 002

Sample preparation: embedded in glycerine

Transmitted-light microscopy: yes (photo)

Observations:

Lime or maple: homocellular wood rays, spiral thickening of the vessel walls, with simple perforation plates and vertical parenchym

[Heiser, Conservation Documentation (als pdf) 2013, 131 - 150]

Sample List Heiser

Cross section No.: QS 10461

Brief description: numerous varnish layers

Sampling location: angel's wing, feather green with yellow

Sample preparation: embedded in light-curing resin (Technovit 2000LC)

Sample No.: 003b

Incident light microscopy: yes (photo)

UV light: yes (photo)

Observation:

1. white ground

2. black underpaint

3. dark green paint layer

4. varnish

5. varnish

Comments:

The UV-light photograph suggests the presence of two layers of varnish. Above are wax remnants.

[Heiser, Conservation Documentation (als pdf) 2013, 131 - 150]

Sample List Heiser

Object No.: DE_SKD_SKS_SAV2200_FR-none

Thin section No.: H1

Brief description: wood sample from the panel

Sampling location: at the bottom right edge of the panel

Sample No.: 001

Sample preparartion: embedded in glycerine

Transmitted-light microscopy: yes (photo)

Observations:

Fir: single row of bordered pits in the tracheids, no resin channels, wood rays: homocellular with taxoid cross field pits and cells with rectangular crystals

[Heiser, Conservation Documentation (als pdf) 2013, 131 - 150]

Sample List Heiser

Cross section No.: QS 10436

Brief description: layer structure of the green paint

Sampling location: angel's wing, feather green with yellow

Sample preparation: embedded in light-curing resin (Technovit 2000LC)

Sample No.: 003a

Incident light microscopy: yes (photo)

UV light: yes (photo)

EDX: yes (see Examination Report )

Observations:

1. White ground

2. black underpaint

3. dark green layer

4. yellow layer

5. varnish

6. wax

Comments:

A black underpainting was applied to the white ground. Over this a dark green paint layer was applied and the fethers were in part nuanced with yellow touches. Numerous varnish layers.

EXD results revealed a thin lead white layer (imprimatura) not visible in the cross-section over the the chalk based ground. The green layer consists of lead-tin-yellow, verdigris and lead white. The final layer contains gipsum, clay (Si, Al, K), as well as local lead and copper.

Cross section No. 4.: QS 10436

Brief description: layer structure of the green paint

Sampling location: angel's wing, green feather

Sample preparation: embedded in light-curing resin (Technovit 2000LC)

Sample No.: 004

Incident light microscopy: yes (photo)

Staining test for protein: Ponceau-S-Red (in a solution of 1% acetic acid) (photo)

Staining test for oil: Sudan black B (in a solution of Isopropanol) (photo)

Observations:

1. white ground

2. black underpaint

3. mid-green paint layer

4. dark green paint layer

5. varnish

Comments:

A black underpaint was applied over the ground. Subsequently a mid-green and a dark green layer were applied. There are small dirt or pigment particles in the varnish layer.

The weak red staining in the ground layer indicates the presence of protein. The black staining shows a layer containing oil ( the imprimatur) between the ground and the subsequent paint layers.

[Heiser, Conservation Documentation (als pdf) 2013, 131 - 150]

Sample List Heiser

Cross section No.: QS 10463

Brief description. layer structure of the blue paint (including retouching)

Sampling location: clouds, original, fill material, retouches

Sample preparation: embedded in light-curing resin (Technovit 2000LC)

Sample No.: 005

Incident light microscopy: yes (photo)

UV light: yes (photo)

Staining test for protein: Ponceau-S-Red (in a solution of 1% acetic acid) (photo)

Observations:

1. white ground

2. dark blue paint layer

3. mid-blue paint layer

4. light blue paint layer

5. transparent layer

6. white fill material

7. transparent isolating layer

8. blue retouches

9. varnish

Comments:

Original paint layers: white ground and blue paint layers. Later additions: transparent layer, the white fill material, a transparent isolating layer, blue retouching paint and a varnish.

The red staining shows a considerable difference between the ground (degradation of the protein) and the more recent fill material. (see frame, QS-10435.)

Scraping: 6 P6

Brief description: binding medium of the blue retouching paint

Sampling location: clouds, retouches

Analysis method: FT-IR

Comments:

The binding medium is a drying oil and is mixed with prussian blue and lead white as well as various saponification products

[Heiser, Conservation Documentation (als pdf) 2013, 131 - 150]

Sample List Heiser

Cross section No.: QS 10435

Brief description. layer structure on the frame, gilding

Sampling location: frame

Sample preparation: embedded in light-curing resin (Technovit 2000LC)

Sample No.: 007

Incident light microscopy: yes (photo)

UV light: yes (photo)

Staining test for protein: Ponceau-S-Red (in a solution of 1% acetic acid) (photo)

Staining test for oil: Sudan black B (in a solution of Isopropanol) (photo)

EDX: yes (see examination report)

Observations:

1. white ground

2. red bole

3. metal leaf

4. transparent coating

5. transparent coating

Comments:

A red bolus was applied to the white ground and subsequently covered with the metal leaf. There are two transparent coating layers over the metal.

The red staining of the ground suggests a proteinaceous binding medium. The black staining of the red layer suggests the presence of oil.

EDX results: the ground contains chalk; copper is present in the red layer; the metal is brass; the coatings layers contain some lead as well as dirt particles.

[Heiser, Conservation Documentation (als pdf) 2013, 131 - 150]

DESCRIPTION

Tools/Materials:

- fluid, black medium; brush

Type/Ductus:

- freehand underdrawing

- thin lines

Function:

- relatively binding for the final painted version; lines delineate contours and indicate the essential features; no representation of volume

Deviations:

- numerous adjustments made during the painting process ; changes (e. g. the size of the angels’ heads and wings; the painted shape of the Gloriole is not indicated in the underdrawing

INTERPRETATION

Attribution:

- workshop Lucas Cranach the Elder

Comments:

- probably with reference to a pre-existing design

[Smith, Sandner, Heydenreich cda 2014]

The semi-circular panel consists of five horizontally aligned planks, rounded at the top. The planks are approximately three centimeters thick and vary in width from between 11 cm to 21.5 cm. They were not glued together with great expertise: the lower join of the central plank glued heartwood and sapwood together.

[Heiser 2013, 35]

The white ground consists of chalk bound in a proteinaceous medium applied in a number of layers. This corresponds with the traditional use of a glue-chalk ground on wooden panels. The ground was then carefully smoothed, only isolated marks are visible. Subsequently an oil-bound imprimatura containing lead white was applied. In addition to acting as an isolating layer it also increased the luminous reflectance of the ground layer for the paint layer, which followed.

[Heiser 2013, 38]

The composition is fixed in the underdrawing, which is visible to the naked eye and almost completely revealed in the infrared reflectogram. It is a generous and energetic drawing executed with a pointed brush in a black fluid drawing medium. The outlines and a few inner forms were defined with single, dynamic lines without employing hatching-strokes. There are a few rare corrections of shapes or forms as can be observed in Christ’s leg and the arrangement of the folds in the loincloth. The ends of the folds are indicated with small hooks and arcs.

The underdrawing was considered during the painting process without being adhering to exactly or being completely binding. The expressions on the angels’ faces have been retained, but the heads were generally painted slightly larger than they had been drawn. The same can be observed with the wings of the angels. Some change completely in size and position in the painted version. The painted version does not follow the border of the clouds established in the underdrawing and the painted shape of the Gloriol is not recorded in the underdrawing. There is no indication that the design was transferred from a pre-existing template. The few, confident lines and rare corrections with regards the angels‘ faces and Christ’s body suggest, that the underdrawing was developed freely on the ground with reference to a pre-existing design. Exemplary is the depiction of Christ’s face. The direction of his gaze is conveyed by only two circles and the indicated eyebrows. The great similarity of the painted version with other depictions of Christ suggests that the artist drew on a large repertoire of forms. God the Father’s head on the other hand, which is a significant element in the composition, is drawn with great attention to detail. The face is also similar to the general type of other Holy Trinity images from Cranach the Elder’s workshop. A comparison with the painting of ‘The Holy Trinity adored by the Virgin and St Sebastian’ in the Museum der Bildenden Künste in Leipzig makes this particularly evident. The considerable difference in the attention to detail in the underdrawing suggests that a less precise design existed for God’s face and that the underdrawing required further elaboration in this area. It is also possible that it was drawn by two different hands.

The stylistic qualities of the underdrawing support the attribution of the panel to the workshop of Lucas Cranach the Elder. A rational underdrawing type influenced by the workshop practice was characteristic for the years between 1510-1520. The style of the underdrawing on the painting from Ehrenberg suggests it was created in the workshop of Lucas Cranach the Elder. In the years between 1510 and 1520 Cranach’s underdrawing was less spontaneous than in previous years when the workshop was smaller. Common to both Cranach and his workshop members are ‘the sparse definition of inner forms, the linear outer forms, the crescent-shaped arcs, the use of loops and open hooks to indicated folds and the omission of hatching-strokes.’

[Heiser 2013, 40-41]

The painting appears to have been executed in oil or oil/resin. Tempera may have been employed for the underlying layers. Lead white, lead-tin yellow and copper green were identified in a cross-section of a paint sample from the green angel’s wing. This corresponds with the pigments used by the Cranach workshop. The paint application is smooth and was executed in thin layers with very few areas of impasto and yet separate areas have been worked up differently. Whereas the clouds and the exterior of God’s coat were laid in with a layer of black paint the blue wings exhibit an ochre underpaint. In the lighter areas the white imprimatura was left visible. A flat application of paint was applied over the underpaint and was subsequently modulated. The modulation of light and dark was achieved with dark glazes, white highlights and further coloured glazes and the white imprimatura lends the whole painting a particular luminosity. The silk material of God’s undergarment was created in the manner mentioned. In 1555 Johann Neudorffer noted that Lucas Cranach could paint the best velvet. The material quality of the painted velvet was achieved by applying red glazes over a black underpaint and completing the effect with bright red highlights. The prevailing black underpaint is a technique used in the Cranach workshop, which was also easy for workshop members to imitate. On the hem of the coat a brownish-orange tone was used, that is typical of the Wittenberg workshop for draperies and jewellery. Elements like the hair or the decoration on the coat and God the Father’s tiara are represented with great attention to detail and are rich in contrast. The intention to create different effects is reflected in both a variation in the methods of paint application as well as the manner in which the painting was worked up: softly blurred transitions feature as does brushwork employing stipples and dashes, and less nuanced areas contrast with calligraphic representation of form.

The flesh paint consists of brown and red glazes applied over light coloured flesh paint. Lead white highlights are only visible to a small extent with the naked eye or in the x-radiograph, suggesting a rapid paint application in not many layers. Heydenreich states that the more complicated painting technique was reserved for the more superior commissions. The sequence of paint application can be established from the overlapping of areas of paint. It corresponds to a greater extent with the usual procedure in the Cranach workshop. First the initial layer of flesh paint and the gloriole were applied. The infrared reflectogram shows that both extend beyond the lines of the underdrawing. The underpaint in the background and the blue angel’s wings followed, while holding single areas in reserve. An unmodulated paint layer was applied at this stage to other areas. The subsequent layers of glaze were complemented by details and dark contours that were in part painted wet-in-wet.

During the painting process the artist corrected forms defined by the underdrawing, which '[reflects Cranach‘s] spontaneous working method and his urge to achieve artistic perfection.' The division of labour so typical of Cranach’s workshop practice cannot be reconstructed on the panel from Ehrenberg depicting the Holy Trinity as little difference in the painterly quality could be established.

[Heiser 2013, 41-42]

The frame is made of a light hardwood, probably lime or maple. It consists of five elements. The x-radiograph shows that these elements were butt-joined. Any further indication about the glue type could not be established through the compact structure of the coating. The frame is only 3 cm wide.

With its simple profile consisting of a large cove and a flat ledge the frame corresponds with the profile of former shrine cases and can be found on other frames from the Cranach workshop. The uncoated transverse section of the the batten at the bottom right exhibits marks from a flat carving tool. It is probably the original frame, which was attached to the front of the panel with nails. On the one hand the original paint layers exhibit a barbe corresponding with the frame and there are no marks on the reverse from former battens.

[Heiser 2013, 37]

• the support is in stable condition, with the exception of a few losses

• the ground of the original paint layers as well as the fills have loosen due to the degredation of the binding medium and tension within the painting; they are in danger of flaking off

• the surface dirt and the attached japanese paper makes it difficult to appreciate the panel painting

• there are only a few remnants of the original frame finish; these are visible in the losses

[Heiser 2013, 49, 52]

• surface cleaning of painting and frame

• removal of the temporary wax consolidation

• consolidation of the paint layers and the frame

• reverse of the panel cleaned

• loose wood reattached

• reconstruction of frame with wooden insert

• varnish removal

[Heiser 2013, 68-74]

The panel was restored by the gilder Otto Puckelwartz and the painter Ernst Knaur:

• the frame members were reconstructed

• the frame was re-coated [re-gilded?]

• losses retouched and areas of original paint overpainted

[Heiser 2013, 44]

A provisional wax-consolidation of the flaking paint on the shrine and the sculptural elements was carried out by the master painter Mebert.

[Heiser 2013, 26]