by Peter and Ann Mactaggart
Pigment ID using Polarised Light Microscopy is a suite of files which was conceived and produced by the late Peter Mactaggart* to help those using the polarising microscope to identify classic pigments.
This suite of files provides information on traditional pigments and a key to help in their identification when viewed, as dispersions, with a polarising microscope. Some of the microscope techniques involved are also discussed.
We have placed this resource on our website, in a modified form, to be available freely to all who may be able to make use it. It should be noted that the information was current in 2007 and should be treated as such. We hope that this is a useful and fitting tribute to someone who, over a long period of time, taught many painting and other conservators.
*Peter Mactaggart who died in April 2020 at the age of 89, taught many conservators how to identify pigments using polarised light microscopy. He taught a maximum of 4 participants on each course at his home… initially at Welwyn and later near Chard, Somerset. He stopped teaching in 2016 to look after his wife Ann, having ran his course in cooperation with us at IAP for more than 15 years. The popularity of his 5 day course never waned… the participants would keep him in class until 7pm some evenings and when he eventually discontinued the course there was a long waiting list of potential participants.
(Peter and Ann published many books (under the name Mac and Me) on various subjects including Dressmaking and Decorating Harpsichords but the most successful book, still in print (Archetype Publications Ltd) is Practical Gilding).
Contents:
- Pigments
Blue pigments
Green pigments
Yellow pigments
Red pigments
Purple and violet pigments
Black and Brown pigments
Strongly Pleochroic
White pigments, extenders and other coloured pigments that are likely to appear colourless under the microscope in transmitted light - Optics
Refractive index
Illumination in transmitted light
Dispersion staining - Menu of techniques
Setting up the microscope
Setting up the lamp
Focal length and magnification
Slide making with Meltmount
Slide making with Glycerine gel
Cover slips
Interference colours and birefringence
The red plate
Uniaxial crystals and twinkling
Refractive index relative to the mounting medium
Pre-decimalization currency
Test yourself - Glossary
- Bibliography
Written and prepared by Peter and Ann Mactaggart
Copyright Peter and Ann Mactaggart. Last updated during June 2007.
Please note this collection of information is copyright and should not be copied. The material is supplied only on the basis that the user acknowledges that the authors do not claim that the identification system is either fool proof or complete. That anyone who uses this system must be responsible for any identifications that are made with its help. The techniques described are ones that have been used and taught by the authors, but it is up to the user to establish whether they should be regarded as safe or sound in their particular circumstances.
If quoting from this resource please see the citation examples at the bottom of each page.
