Notes to the User
The paintings catalogued here are arranged by schools of painting—Italian, Spanish, Dutch, English, Flemish/Netherlandish, French, and German/Austrian—to show the breadth of Dr. Clowes’s collecting practice. This organizational strategy gives a nod to the last overview of the Clowes Collection published in 1973 by A. Ian Fraser, A Catalogue of the Clowes Collection, which is arranged in this manner.
Each school is subsequently divided into “Featured Works,” masterpieces receiving a complete assessment, consisting of an art historical entry 
, as well as a complete technical examination report 
. Within each category the paintings are arranged in rough chronological order. “Additional Works” of lesser stature are listed below the “Featured Works” section. These paintings are identified with basic information only.
A previously unpublished manuscript documenting the Clowes Collection was authored by the art historian Dr. Mark Roskill. Produced in the years 1965–1968, it was delivered as a typescript to Allen Whitehill Clowes in December 1968. It is reproduced here for the first time, by permission of his son, Damian Roskill. Roskill’s entire manuscript appears as a PDF at the back of this catalogue, while individual entries by Roskill are linked to each individual artwork with the icon 
. In this manner, the dramatic changes in how art historical texts were presented from 1968 to 2022 are highlighted: Roskill produced his manuscript on a typewriter, now clearly a tool of the past, and this digital catalogue uses web-based design tools, incorporating zoomable images within the body of text, and facilitating user navigation by allowing toggling between parts of an entry, and between catalogue entries and technical examination reports with a simple “click.” As conceived, this digital catalogue blends art historical inquiry and detailed technical conservation analysis, as well as old and new presentation technologies, making it of interest to multiple research communities.
Each Catalogue Entry opens with the accepted title of the painting and its date of creation. This is followed by the author of the painting, medium and dimensions (in both inches and cm, with height preceding width), credit line, and accession number. Many of the paintings in the Clowes Collection are executed on wood panels; when known, the type of wood is identified. (Detailed information about dendrochronology and/or dating of the wood panels is included in the Technical Reports section, see below.) Marks, inscriptions, and distinguishing features that appear on the front of the painting are part of the first section of identifying information.
The following terms pertaining to the authorship of a painting are used in cases when an artist cannot be identified with certainty:
Attributed to: Indicates that a degree of uncertainty exists surrounding the attribution. This may be due to iconographic or stylistic reasons, or as a result of the condition of the work.
Workshop/Studio of: Indicates that the work was created in the named artist’s workshop or studio, with the possible participation of the named artist. The work in question may have left the workshop as the named artist’s work.
Master of [place name or artwork]: Indicates authorship by an anonymous painter who is linked to a particular place, or to a significant artwork representative of the anonymous painter’s style.
Unknown Artist: Indicates that the identity of the artist has not or cannot be determined. The work in question, however, can be linked to certain stylistic characteristics, so this designation is generally followed by a likely place and approximate time of creation.
Circle of: Indicates that the work was created by an unidentified contemporary of the named artist, working in a similar style.
School of: Denotes a group of painters who worked under the influence of a single artist, as in “School of Raphael” or “School of Fra Angelico.”
Follower of: Indicates that the work was created by an unidentified artist working in the named artist’s style. Association with the named artist is possible though undocumented, but historical continuity is assumed.
After: By an unidentified artist, painted as a copy, or near copy.
Art historians from around the world were contracted to write entries for paintings in their particular areas of expertise. (See the Authors & Contributors on the drop-down menu of this catalogue.) A significant number of the catalogue entries were authored by former Allen Whitehill Clowes Curatorial Fellows at the Indianapolis Museum of Art.
The Provenance section lists all known owners, their life dates and location when known, and the years of ownership. A semicolon between owners indicates a direct transfer; a period between owners indicates uncertainty in the chain of ownership. Ownership by entities who served as art dealers is indicated with parentheses. In compliance with AAM provenance guidelines, provenance information is heavily footnoted, citing sources in detail. Many letters and documents listed in this section come from the Clowes Registration Archive at the Indianapolis Museum of Art at Newfields. These archival materials were transferred to the Indianapolis Museum of Art, now the Indianapolis Museum of Art at Newfields, when the Clowes Collection was received on long-term loan in 1971.
Each Exhibitions section records the exhibition history of a particular artwork through 2022 and is as complete as possible. The References section includes only sources that specifically mention the Clowes Collection artwork, listed chronologically. On select occasions, when an author chose to call attention to details about a painting’s execution, a section entitled Technical Notes is appended to the entry.
Technical Examination Reports form an equally important aspect of this digital catalogue. During each examination, the paintings were unframed, examined, and photographed with state-of-the-art equipment by paintings conservators, forming the basis of each report. Each Technical Examination Report opens with a standardized image carousel systematically documenting the following instrumental methods: front and back, visible light; front, raking light; front, ultraviolet-induced visible florescence; front, infrared reflectography; X-radiography; and frame, front and back, visible light. Images taken during treatment also appear in the carousel when relevant.
Each Technical Examination Report begins with an Overview, noting basic information about the object and identifying the conservator/conservation scientist who undertook the detailed analysis. This is followed by a section identifying Distinguishing Marks on both front and back of the painting, including images of the “marks” in question. These include inscriptions, stamps, labels, etc. A Summary of Treatment History outlines the documentary and physical evidence of past treatment interventions. The Current Condition Summary discusses the condition of the work at the time of examination. A table identifying Methods of Examination, Imaging, and Analysis used to examine each object follows.
A section on the painting’s support (Description of Support and Condition of Support) discusses materials and construction of the support and auxiliary supports as well as their condition and presumed (or confirmed) age. The section on the ground layer (Description of Ground and Condition of Ground) discusses the materials and application of the preparatory layers as well as the stability and condition at the time of examination. The section on the Description of Composition Planning discusses any underdrawing, preparatory layers, and pentimenti that were observed during the examination of the object. The section on the paint layer (Description of Paint and Condition of Paint) includes analysis of the binding media and pigments as well as a discussion of the techniques and tools used by the artist to create the work and a discussion of the condition of the original paint layer. The coatings section (Description of Varnish/Surface Coating and Condition of Varnish/Surface Coating) describes the layers of varnish, dirt, and other surface materials as well as inpainting, retouching, and overpaint present along with the condition of the surface coatings at the time of examination. Finally, the frame section (Description of Frame and Condition of Frame) discusses the presumed age, style, construction, and condition of each frame. There is a Distinguishing Marks section for labels, stamps, inscriptions, etc. found on the frames. These marks are numbered sequentially with any already noted at the beginning of the report.
In addition to being examined and photographed in visible light (front and back), raking light, ultraviolet-induced visible fluorescence, infrared reflectography, and X-radiography, paintings were also examined with a stereomicroscope. Each work underwent pigment analysis using XRF, and in select cases, cross sections were taken and analyzed using SEM-EDS. In some cases, pigments and ground materials were analyszed using Raman microspectroscopy. Binding media were analyzed where appropriate using FTIR.
Equipment used to carry out analysis for this catalog include:
Cross-section analysis:
Cross sections of paint layers were prepared by mounting an excised sample in Buehler Epoxi-cure mounting medium. The samples were pre-oriented in the mounts using a drop of fast-drying Superglue. Once the poured resin had cured fully, the section was polished on Micromesh cloth up to 12,000 grit fineness. Darkfield images of the sectioned samples were acquired on a Zeiss AxioImager M2m compound microscope with a 20X objective using an MRc5 digital photomicrography camera. The same area was then examined under UV irradiation from an X-cite 120Q mercury vapor lamp source for signs of visible luminescence. A DAPI filter cube set allowed narrowband excitation between 325 and 375 nm with observation throughout the visible spectrum (λem > 412 nm).
Fourier transform infrared (FTIR):
Fourier transform infrared (FTIR) microspectroscopy was performed on a Continuum microscope with a liquid nitrogen cooled MCT A detector coupled to a Nicolet 6700 spectrometer purged with dry, CO2-free air. The spectra are the sum of 32 coadditions at 4 cm-1 spectral resolution. Microsamples were crushed on a diamond compression cell and held on a single diamond window during the analysis. Sample identification was performed using the Infrared and Raman Users Group (IRUG) reference spectral library.
Fourier transform infrared (FTIR) spectroscopy was performed using a SpectraTech Smart Orbit diamond ATR attachment coupled to a Nicolet 6700 spectrometer with a mid-IR DTGS detector. The instrument was purged with dry, CO2-free air. The spectra are the sum of 64 coadditions at 4 cm-1 spectral resolution. Sample identification was performed using the Infrared and Raman Users Group (IRUG) reference spectral library.
Raman microspectroscopy:
Raman spectra were acquired using a Bruker Senterra microspectrometer on a Z-axis gantry. The spectrometer uses three selectable excitation lasers (532, 633, and 785 nm), an Andor Peltier-cooled CCD detector, and a 50 μm confocal pinhole. Laser power at the sample was generally below 5mW. The spectra are the result of 5 or 10 sec integrations with 5–30 coadditions. A 50X ultra-long working distance objective was used to focus slightly below the varnish layer on select pigment particles. The analysis spot size was on the order of 1 μm, and the spectral resolution was in the range of 9-18 cm-1. OPUS software allowed for automated cosmic spike removal, peak shape correction, and spectral calibration.
Scanning electron microscopy with energy dispersive spectrometry (SEM-EDS):
Electron micrographs of cross sections were created using a Zeiss EVO MA15 scanning electron microscope operated in variable pressure mode at 50 Pa of room air. A five-segment backscattered electron detector (BSE), a variable pressure secondary electron detector (VPSE), and a Bruker XFlash 6 energy dispersive spectrometer (EDS) with 60mm2 area were used to acquire images. Electron accelerating voltage was set at 20 keV to ensure generation of X-rays for all metals in the sample with a beam current of 1.2 nA. A sample working distance of 8.5mm optimized EDS detection. The SEM was controlled using Zeiss SmartSEM software while the EDS spectra were collected and analyzed using Bruker Esprit 2.0 software.
X-ray fluorescence (XRF):
A Bruker Artax microfocus XRF with rhodium tube, silicon-drift detector, and polycapillary focusing lens (~70 μm spot) was used in the analysis. Experimental parameters included 50 keV tube voltage, 600 μA current, and 60 sec live time acquisitions. A helium purge gas allowed for light element detection. Elemental survey spectra were collected in the region from 0 to 50 keV.
Point analyses and elemental maps were acquired on a Bruker M6 Jetstream macro-scanning XRF with rhodium tube, dual 60 mm2 silicon-drift detectors, and polycapillary focusing lens (selectable 540 to 100 mm spot). Experimental parameters included 50 keV tube voltage, 600 mA current, and 45 msec/pixel scan rate. Elemental spectra were collected in the region from 0 to 40 keV.
A Bruker Tracer 5i handheld XRF with rhodium tube, a large area silicon drift detector, and a 3 or 8mm collimator was used in the analysis. Experimental parameters included 40 keV tube voltage, 100 μA current, and 60 sec live time acquisitions. A vacuum attachment allowed for light element detection. Elemental survey spectra were collected in the region from 0 to 40 keV.
Macro X-ray fluorescence scanning (MA-XRF):
Point analyses and elemental maps were acquired on a Bruker M6 Jetstream macro-scanning XRF (MA XRF) with rhodium tube, dual 60 mm2 silicon-drift detectors, and polycapillary focusing lens (selectable 540 to 100 mm spot). Experimental parameters included 50 keV tube voltage, 600 mA current, and 45 msec/pixel scan rate. Elemental spectra were collected in the region from 0 to 40 keV. Maps were prepared from deconvoluted and background corrected spectra. Overall image intensities were manipulated to enhance readability of the maps.
Pyrolysis–gas chromatography–mass spectrometry (PY-GC-MS):
A small scraping of paint was characterized by PY-GC-MS. The sample was analyzed using the method similar to Tsuge et al. In short, a Frontier Lab PY-3030D double-shot pyrolyzer system with a 320oC interface was coupled to a Thermo Trace Ultra gas chromatograph and an ISQ single quadrupole mass spectrometer. A Thermo TG-5MS capillary column (30 m x 0.25 mm x 0.25 µm) was used for the separation with 1 mL/min of He as the carrier gas. The split injector was set to 250oC with a split ratio of 100:1. The GC oven temperature program was 40oC for 2 min, ramped to 320oC at 20oC/min, followed by a 13 min isothermal period. The MS transfer line was at 320oC, the source at 230oC, and the MS quadrupole at 150oC. Mass spectra were collected from 29–250 amu for the first 3 min and from 45-600 amu thereafter. The electron multiplier was set to the auto-tune value. Samples were placed into a 50 µL stainless steel Eco-cup and pyrolyzed at 600C for 6 sec. If necessary, the sample was derivatized on-line using 3 μL of 25 wt% tetramethylammonium hydroxide (TMAH) in methanol from Sigma-Aldrich and allowed to dry before introduction into the pyrolyzer. In all instances, the sample cup was purged with He for at least 3 min in the microfurnace prior to pyrolysis. For derivatized samples, a 3 min solvent delay was added to the run prior to activating the MS. GC peak identification was aided by searching the NIST MS library and by comparison to pyrograms of authentic samples.