Technical Report

Technical Summary

Claude Monet’s Stacks of Wheat (Sunset, Snow Effect) was painted on a pre-primed, no. 40 seascape (marine) standard-size linen canvas. The ground consists of a single, off-white layer. A stamp from the color merchant Troisgros Frères was documented on the back of the original stretcher. A warp-thread match was detected with seven other Monet paintings from the Art Institute’s collection: The Petite Creuse River (cat. 25 [W1231], inv. 1922.432), Stacks of Wheat (End of Summer) (cat. 27 [W1269], inv. 1985.1103), Stacks of Wheat (End of Day, Autumn) (cat. 28 [W1270], inv.), Stack of Wheat (Thaw, Sunset) (cat. 32 [W1284], inv. 1983.166), Sandvika, Norway (cat. 34 [W1397], inv. 1961.790), Branch of the Seine near Giverny (Mist) (cat. 36 [W1475], inv. 1933.1156), and Water Lily Pond (cat. 37 [W1628], inv. 1933.441), suggesting that the fabric for these paintings came from the same bolt of material.3 The painting is densely built up from a light-toned underpainting that laid out the main forms of the composition. In the process of painting, the artist made a significant change to the placement of the two stacks. At an earlier stage, the stacks appear to have been of a size comparable to those depicted in the final painting but were placed much further apart, closer to the left and right edges of the canvas. The horizon line also appears to have been painted in a significantly lower position in the earlier image. Some of the brushwork related to the earlier painting remains visible on the surface. The date, 91, appears to have been applied later and in a different color from the signature, after some pink brushstrokes added to the bottom right corner covered the original date.

Multilayer Interactive Image Viewer

The multilayer interactive image viewer is designed to facilitate the viewer’s exploration and comparison of the technical images (fig. 29.1).4

Signature

Signed and dated: Claude Monet 91 (lower right, name in reddish-brown paint, date in greenish-brown paint)5 (fig. 29.2, fig. 29.3, fig. 29.4). The signature is executed in a reddish-brown paint and was applied when the underlying paint was dry. The date, on the other hand, consists of a dull, greenish-brown paint mixture and appears to have been added later, wet-in-wet, over a layer of pale-pink paint that was applied just to the corner area and that appears to cover an earlier date similar in color to the signature (fig. 29.5).6

Structure and Technique

Support

Canvas

Flax (commonly known as linen).7

Standard format

The original dimensions were approximately 65 × 100 cm, which corresponds to a no. 40 seascape (marine) standard-size stretcher.8

Weave

Plain weave. Average thread count (standard deviation): 23.3V (0.5) × 22.2H (0.7) threads/cm. The vertical threads were determined to correspond to the warp and the horizontal threads to the weft.9 A warp-thread match was determined with seven other Monet paintings in the Art Institute’s collection: The Petite Creuse River (cat. 25 [W1231], inv. 1922.432), Stacks of Wheat (End of Summer) (cat. 27 [W1269], inv. 1985.1103), Stacks of Wheat (End of Day, Autumn) (cat. 28 [W1270], inv. 1933.444), Stack of Wheat (Thaw, Sunset) (cat. 32 [W1284], inv. 1983.166), Sandvika, Norway (cat. 34 [W1397], inv. 1961.790), Branch of the Seine near Giverny (Mist) (cat. 36 [W1475], inv. 1933.1156), and Water Lily Pond (cat. 37 [W1628], inv. 1933.441).10

Canvas characteristics

There is mild cusping along the top and bottom edges, slightly more pronounced cusping on the left edge, and stronger and more irregular cusping along the right edge.

Stretching

Current stretching: Dates to the 1992 treatment (see Conservation History); copper tacks spaced approximately 2–5 cm apart. The painting appears to have been mounted on the stretcher slightly askew. Additional holes on all sides probably relate to the aluminum strip molding applied in 1959 (see Conservation History).

Original stretching: Tack holes, spaced approximately 6–8 cm apart, correspond to cusping in the canvas. A second series of tack holes is spaced more irregularly, approximately 5–10 cm apart, and does not align with the cusping pattern.11

Stretcher/strainer

Current stretcher: Five-membered wood stretcher with vertical crossbar and keyable mortise and tenon joints, dating to the 1992 treatment (see Conservation History). Depth: 3 cm.

Original stretcher: Discarded. The pre-1968-treatment stretcher may have been the original stretcher.12 A diagram in the 1959 examination report indicates that the stretcher consisted of five members including a vertical crossbar, with keyable, butt-ended joints.13 Depth: Based on the presence of a crease in the tacking margin, presumably where excess fabric was folded over the back edge of the original stretcher, the depth was approximately 1.5 cm.

Manufacturer’s/supplier’s marks

The 1959 examination report records that there was a stamp on the back of the pre-1968-treatment stretcher (discarded): TROT [sic] . . . (?)OS FRÈRES / 35 Rue Victor Massé / Panneaux etc (fig. 29.6).14

Preparatory Layers

Sizing

In UV light, evidence of a light blue fluorescence between the canvas and the ground suggests the presence of an organic layer, possibly glue sizing (fig. 29.7).15

Ground application/texture

The ground layer extends to the edges of all four tacking margins, indicating that the canvas was cut from a larger piece of primed fabric, which was probably commercially prepared. The ground consists of a single layer and ranges from approximately 15 to 80 µm in thickness (fig. 29.8).

Color

The ground is off-white, with some dark particles visible under magnification (fig. 29.9).

Materials/composition

Analysis indicates the presence of the following components: lead white and calcium carbonate (chalk), with traces of bone black, iron oxide, alumina, silica, and various silicates.16 Binder: Oil (estimated).

Compositional Planning/Underdrawing/Painted Sketch

Extent/character

No underdrawing was observed with infrared reflectography (IRR) or microscopic examination.

Paint Layer

Application/technique and artist’s revision

Most of the landscape and the left side of the sky were executed in similarly soft shades of blue and pink, sometimes mixed to form pale-purple hues. These colors appear throughout these areas, but in general, pink was used for the reflections in the snow and a slightly more intense blue to denote the shadows. The artist worked in a fairly narrow tonal range, such that the transition from foreground to middle ground to sky is almost indistinguishable and the buildings in the distance are barely discernible. The stacks come into sharper focus through the use of more intensely colored strokes of blue and reddish-brown paint. The most intense color—shades of bright yellow, orange, and salmon pink (fig. 29.10)—were reserved for the evening sky. The paint layer is fairly continuous, with very little exposed ground visible at the surface. The dense buildup of paint is evident in both the transmitted light and X-ray images (fig. 29.11). Where a few small glimpses are afforded, there appears to be a light-toned underpainting that covers most of the ground layer. This often consists of pale shades of gray (fig. 29.12) or, underneath the stacks, subdued greens and pinkish browns (fig. 29.13, fig. 29.14). The brush-marked texture of this underpainting often remains visible on the surface of the painting.

The brushwork is relatively uniform over the surface. Brush marks are visible, but they are low relief and smoothed out in places, with very little impasto. The paint consistency ranges from quite fluid, exhibiting a smooth, settled surface with some swirling together of unmixed colors (fig. 29.15), to stiffer, more-bodied paint that holds the ridges of the brush marks (fig. 29.16).17 The painting combines areas of wet-in-wet mixing and wet-over-dry brushwork. In some areas, the artist used a scumbling technique in which he layered opaque, slightly more intense color on top of a lighter paint layer. This is apparent in the orange area of the sky, where deep orange-red paint was applied wet-over-dry with a small brush (2.0–3.0 mm in width), using short strokes that allow the pale orange layer underneath to show through (fig. 29.17). A similar effect was observed in the bluish-gray hill near the left edge (fig. 29.18). The light dragging of the upper paint layers here and throughout the painting emphasizes the texture of the underlying layers. This is particularly apparent in the areas of compositional changes (discussed below).

Technical examination has revealed a major compositional change in the placement of the two stacks. As is evident in both the X-ray and transmitted-infrared images, earlier in the painting process the stacks were positioned much farther apart (fig. 29.19). Although the sizes of both the large and the small stack seem comparable to those in the final painting, their outer edges were much closer to the left and right sides of the canvas, which would have left quite a large empty space in the middle of the composition.18 Brushstrokes from the earlier stacks, particularly the thicker strokes that delineate the edges, remain visible on the surface, especially when the painting is viewed in raking light (fig. 29.20). It is difficult to say how far these stacks were developed or whether they were painted in a different palette, since the paint applied on top is mostly continuous. In a few small areas of the large painted-out stack, however, some green paint was observed below the surface (fig. 29.21). A similar green area was detected below the pink and blue paint of the landscape at the left edge of the painting (fig. 29.22), perhaps providing evidence that the artist started the painting using a different color scheme. The artist may also have adjusted the position of the horizon line. There are some strong, roughly horizontal, curving brushstrokes above and below the current horizon, on the left and right sides of the painting. These are more clearly visible in the X-ray, which shows similar brushstrokes continuing throughout the sky. Based on this evidence, it seems that the horizon line may have originally been significantly lower, possibly with the peak of the large painted-out stack rising slightly above it (fig. 29.23).

A band of disturbed paint—caused by something having been pressed onto and then pulled away from the paint surface when it was still wet, drawing up low peaks—occurred along the bottom edge. The band is approximately 45 cm long and is positioned roughly in the middle of the canvas (29 cm from the left edge and 27 cm from the right edge) (fig. 29.24). This impression in the wet paint may have been caused by an easel cleat or transporting device. Subsequent brushstrokes were applied on top when the peaks of paint were dry, indicating that the disturbance to the wet paint occurred at some point during the execution of the work. A few inclusions, possibly of plant matter, were observed embedded in the paint layer, near the bottom-right corner (fig. 29.25).19

Painting tools

Brushes including 0.3, 1.0, and 1.5 cm width, flat ferrule (based on width and shape of brushstrokes). There are several brush hairs embedded in the paint surface.

Palette

Analysis indicates the presence of the following pigments: lead white, cadmium yellow, chrome yellow, vermilion, red lake, viridian, cobalt blue, and ultramarine blue.20 UV fluorescence suggests the use of red lake throughout the landscape.21

Binding media

Oil (estimated).22

Surface Finish

Varnish layer/media

The painting was cleaned in 1992 and left unvarnished. It has a subtly variable surface—matte in some areas, low sheen in others—depending on the qualities of the paint. It is noted in the conservation file that the painting was cleaned and varnished in 1922.23 Its surface finish prior to this treatment was not documented (see Conservation History).

Conservation History

The painting was cleaned and varnished in 1922.24

In 1954 the stretcher was keyed out to ameliorate slackening of the canvas.25

Around 1959 the painting was surface cleaned with wax emulsions and backed with resin-coated paper board, and aluminum strip molding was attached along the edges.26

In 1968 a “very heavy, yellowed” varnish was removed. The canvas was wax-resin lined and mounted on a new ICA spring stretcher. A layer of polyvinyl acetate (PVA) AYAA was applied. Minor inpainting was carried out. A layer of methacrylate resin L-46 was applied, followed by a final layer of AYAA.27

In 1992 the wax-resin lining was removed. The canvas was edge lined and mounted on a new keyable wood stretcher with a loose lining. The synthetic varnish layers were removed, and the painting was left unvarnished.28

Condition Summary

The painting is in good condition. The canvas is edge lined and loose lined with a panel insert. There are no planar deformations. Moderate cracking, abrasion, and small losses are present in the paint and ground layers around all of the edges, with some short splits in the canvas at the foldovers and holes at the corners. The paint layer is in excellent condition, with only a few tiny flake losses. There is minimal retouching, mostly at the top, left, and right edges. There is an overall network of fine cracks. Cracking is more extensive in the sky, but is visible mostly only under magnification. Stretcher-bar cracks are visible in the area of the original vertical crossbar. A few anomalous brown and gray paint strokes near the bottom left corner have the appearance of smudges or accretions but are probably original to the painting, since they appear to be wet-in-wet with the surrounding paint. There is some flattening of the paint and embedded wood fibers and debris in the frame rebate area, which appears to be due to framing when the paint was still soft. Several brush hairs are embedded in the paint surface. There are some light scratches and gouges in the blue paint at the bottom left corner and also to the right of the large stack, which occurred when the paint was still soft. The painting is currently unvarnished and has a natural matte finish with slight variations in gloss depending on the qualities of the paint. Some yellowed, natural-resin varnish residues and starch-paste residues from previous treatments are visible microscopically in the recesses of the paint texture. In places, these residues scatter the light and impart a whitish, milky appearance at certain angles. There are traces of gold paint in the frame rebate area.
Kimberley Muir

Frame

Current frame (installed in 1995): The frame is not original to the painting. It is a reproduction of a Louis XIII convex frame with carved acanthus leaves divided by an undulating ribbon, inner guilloche ornament bordered by hollows, and leaf-tip sight edge (Paul Mitchell Ltd., London 1995). The frame is water gilded over red bole on gesso. The hollows are burnished while the ornament is selectively burnished. The gilding is toned with thin washes of oil paint and glue size. The carved jelutong-wood molding is mitered and joined with dovetail splines. The molding, from perimeter to interior, is quirked ogee cyma recta; convex face with carved acanthus leaves divided by an undulating ribbon; fillet with rocked recutting; hollow; guilloche bordered by rocked recutting; hollow; torus with carved leaf tips; and cove sight (fig. 29.26).29

Previous frame (a note on a 1969 loan request states the work “was re-framed in 1968 August”; removed 1995): The work was previously housed in an American mid-twentieth-century reproduction of a Louis XVI, gilt, architrave frame with ribbon-and-reel and bead-and-bobbin ornament (APF Inc., New York) (fig. 29.27, fig. 29.28).30
Kirk Vuillemot