Unlocking the English Portrait Miniature: The Materiality of Isaac Oliver's Oeuvre

The portrait miniature is a rare art form that was brought to perfection in Elizabethan and Jacobean England by Nicholas Hilliard (1547 – 1619) and Isaac Oliver (c. 1565–1617). The surviving miniatures, of which the Fitzwilliam holds a collection of national importance, together with a small number of contemporary treatises produced by practitioners of the art, allow a unique insight into a formative period in the development of the country’s visual and political culture.

Nicholas Hilliard, establishing his reputation from the early 1570s onwards (he was shown the rare honour of being commissioned to portray Elizabeth I in miniature in 1572), has received much attention in the past, due in part to his unfinished treatise, A Treatise Concerning the Arte of Limning, through which an opinionated and diligent artistic personality emerges. However, Isaac Oliver, Hilliard’s most famous and arguably more talented pupil, was a highly versatile artist who also excelled in draughtsmanship, but whose artistic scope and technical range is nevertheless much harder to establish in full. This is not least because, unlike his teacher, Oliver is not known to have produced any written documentation about his life and practice.

A pilot study, funded by the Cambridge Humanities Research Grant Scheme and undertaken during 2018–19, approached Isaac Oliver from a technical angle through the undertaking of a study of his working methods, techniques and use of materials as evidenced in approximately ten attributed works, mainly from the Fitzwilliam Museum miniatures collection. A technical and analytical approach was employed, which expanded on the methodology developed for the examination of illuminated manuscripts that fed into the COLOUR: The Art and Science of Illuminated Manuscripts exhibition at the Fitzwilliam Museum (30 July 2016–2 January 2017). The same analytical protocol was furthermore successfully employed during the Hamilton Kerr Institute’s work on the recently acquired National Trust cabinet miniature of Lord Herbert of Cherbury, attributed to Oliver and now exhibited at Powis Castle, in Wales.

The pilot study, although limited in scope, confirmed the potential of the cross-disciplinary approach and of the proposed analytical methodology, which includes technical photography and micrography (in visible and raking light), X-radiography, imaging (in the ultraviolet and near-infrared range) and spectroscopy (FORS, XRF, Raman and FT-IR). It revealed in great detail what paint media and pigments are present in the examined miniatures, and how they were utilised to accomplish such highly refined results. It also clarified questions about later interventions and deterioration phenomena, which on such a small scale can be extremely difficult to chart with the naked eye!

Building on the success of the 2018-19 pilot study, an expanded research project entitled Unlocking the English Portrait Miniature: The Materiality of Isaac Oliver's Oeuvre (Summer 2019–Autumn 2023) was launched with a greatly increased scope. It incorporates more than 80 miniatures attributed to Isaac Oliver, followers of Isaac Oliver and examples by his contemporaries selected from a wide range of collections across Britain and abroad. Analytical data from Isaac Oliver miniatures was collected from the following institutions:

• The Royal Collection (UK)
• Burghley House (UK)
• The National Portrait Gallery (UK)
• The National Trust (UK)
• The National Gallery of Ontario (CA)
• The Swedish National Museum (SE)
• Statens Museum for Kunst in Copenhagen (DK)

With generous support from David Thomson, the online, open-access resource Unlocking the English Portrait Miniature hosting all of the newly acquired material information was created (https://unlocking-miniatures.fitzmuseum.cam.ac.uk).

Following the pilot study, some highlights of which were published in a special issue of British Art Studies, we have received further support from David Thomson with funding from the Ken Thomson Collection at the Art Gallery of Ontario, as well as grants from the British Academy/Leverhulme Small Research Grant Scheme and the Fitzwilliam Museum Marlay Group.

Several institutions have granted access to their miniatures for the purposes of this research. They include the Fitzwilliam Museum (UK), Burghley House (UK), The National Trust (UK), The Buccleuch Collection (UK), The Royal Collection (UK), The National Portrait Gallery (UK), Statens Museum for Kunst in Copenhagen (Denmark), Nationalmuseum in Stockholm (Sweden) and the Ken Thomson Collection at the Art Gallery of Ontario (Canada). We are grateful to all these institutions for their willingness to let miniatures from their collections be included in this research initiative.

The online resource is the first of its kind dedicated specifically to the technical investigation of these minute masterpieces. It offers a state-of-the art viewer feature, with which the miniatures can be explored through high resolution images taken while the miniatures were removed from their protective, glazed lockets during analysis.

The resource viewer displays technical images that reveal new information about pigments, pentimenti and historical interventions. The viewer has curtain- and transparency filter features so that a resource user can toggle their way to seeing more than one image at the same time or overlaid onto other images at varying transparency levels. As the image stacks are perfectly aligned, subtle differences between the technical images of a miniature can be closely compared and interrogated. The IIIF enabled viewer is also designed to allow the side-by-side comparison of several miniatures simultaneously, including IIIF-enabled images of miniatures hosted online by other collections. These can be pulled into the viewer, thereby expanding the number of miniatures that can be compared from collections across the world exponentially.

Non-specialists will find an illustrated dictionary explaining the technical terminology employed throughout the site (https://unlocking-miniatures.fitzmuseum.cam.ac.uk/terminology). The illustrations help to link the information about pigments and materials directly to examples of their use available on the resource. The project team behind the resource and their collaborators also write blog posts about miniatures research.

The technical insights made possible through the interrogation and interpretation of the collected data is helping to unearth Isaac Oliver’s artistic secrets, suggesting a freer use of painting materials than prescribed in Hilliard’s treatise, an experimental streak during the execution rarely evident in the finished works, and a strong connection with the artistic scene on the Continent. A key finding has been the discovery of the mercury chloride compound calomel, employed as an alternative white pigment to the ubiquitous lead white, and research into the use of this highly unusual material is ongoing.

The miniatures research has been generously funded by the Cambridge Humanities Research Grant scheme, the British Academy/ Leverhulme Small Research Grant Scheme, The Fitzwilliam Museum Marlay Group and David Thomson.