The study of Niiro patination through surface science and studio application.

The applicant holds an AHRC Fellowship in the Creative and Performing Arts. The research program is entitled 'The production and application of Japanese alloys and patination' and will run from May 2007- April 2010.

In this application we seek funding to support research into the application of the niiro patination technique which is used to patinate irogane alloys. This research was outlined in the original fellowship application and is central to the overall research program. Funding from AHRC will ensure that the research is carried out to the highest quality.

The Western tradition of metal patination and colouring is based on the use of a small range of metals and alloys which are coloured by the application of a wide range of patination solutions. In contrast to this, Japanese metalworkers developed a wide range of irogane alloys which are coloured with a single patination solution (the niiro eki or boiling colour solution). This approach allows different alloys to be combined in one piece and patinated, producing a multi-coloured piece of metalwork.

There are several barriers to consistent niiro patination. For example, the frequent 'patchiness' of the colour obtained results in time consuming re-polishing and re-patination. Variations in colour and colour consistency make the planning of a workpiece difficult. There is disagreement amongst Japanese craftspeople on the optimum composition and correct application of the niiro patination solution. In this study we aim to develop a reliable and easy-to-use patination process using standard ingredients available in the UK.

The research will ask:

1. How should the surface be prepared prior to patination to ensure even patination?

2. How can we optimize the ingredients and composition of the niiro solution to achieve good patination on the alloys prepared in our earlier study?

3. How should we apply the patination solution to the alloys?

4. What is the full range of colours that we can achieve with the niiro patination solution?

It is proposed to study the effects of niiro colouration on the alloys developed in the previous proposal, paying particular attention to the performance of alloys produced and finished by hand and by semi-commercial processes. Traditional niiro solutions and solutions made with laboratory or commercial grade chemical agents will be tested on both samples and studio work, and any differences between them will be characterised.

A limited number of researchers have published work on the chemistry of niiro patinated surfaces, on surface preparation, and on substitutes for some parts of the traditional recipes. However, a full understanding of the process and the variations that occur is still to be achieved.

The research will be located at Sheffield Hallam University using the facilities and expertise of the Art and Design Research Centre (ADRC) and the Materials and Engineering Research Institute (MERI). There is a strong team of highly experienced and internationally recognised Metalwork and Jewellery staff at ADRC to support the research. MERI has the background of precious metals research, and the extensive equipment and materials characterisation techniques essential to support this research.

Papers will be submitted to scientific, design and craft related journals and at least two conferences. The University website will be utilized for the publication of papers etc. Commercial collaborators will be sought through SHU to exploit any materials or processes that are developed.

This project is a fundamental part of the larger research programme as understanding and control of the niiro solution is crucial to the patination of the irogane alloys. The niiro solution will be tested under laboratory conditions and through studio work. A combination of laboratory based testing on small samples with practice based testing on larger workpieces in the studio will allow for a through study of niiro patination.