Notes: 33)

Laboratory testing of pigments has been possible only
on a limited scale because until very recently it required
detaching particles of paint to he examined under the
microscope. The excellent state of preservation of many
of the portraits and their considerable fragility made them
unsuitable candidates for scrutiny by these methods.
However, several small groups of portraits did undergo
analysis in this way and have confirmed what the
experienced eye - of Tsarouchis, for instance - had seen
already. Analysis conducted by Ramer on Petrie Museum
portraits from Hawara (see 'Technology', p. 5) showed 
the pigments used to be:
-white calcium sulphate (chalk) or lead white
-yellow yellow ochre (one sample contained an unidentified
 yellow organic glaze)
-red red ochre, haematite, minium (red lead)
-brown ochreous earth
-purple-pink lake (unidentified organic dye on a substratum
 of calcium sulphate and/or chalk
-black carbon (charcoal).
The latest technology, which permits tests to be done
without any damage at all to the painting, has been employed
recently at the Benaki Museum in Athens, and by Ashok Roy
in the Scientific Department of the National Gallery in London.