As far as the visual identification of these things, here's what helps:
Make several hundred carbon/carbro prints using every conceivable
combination. After a while you become real good at identifying carbon
prints and by default, woodburytypes.
BTW, I do recommend those interested in the woodburytype to become familiar
with carbon transfer first. The chemistry/relief business is much the same,
but the carbon print will tell you right away if you are making a decent
print. If you can't get an excellent woodburytype you are left wondering
whether the problem is at the mould making stage or at the liquid ink
stage.
>
..
>The question is probably pretty academic for most us without the resources
>and expertise of the conservation section in the Getty Museum, but perhaps
>the only way to non-destructively determine whether the plates in Terry's
>book are woodburytypes might involve using x-ray diffraction spectroscopy to
>test for traces of chromium. Some probably remain in a carbon print (Luis?),
>but the 'ink' used to produce woodburytypes would consist solely of gelatine
>and colouring matter.
Not necessarily. Chrome-green was a very popular pigment. I have seen many
green carbon and bromoil prints, though not woodburytypes. Most colors were
produced by a mixture of pigments.
This said, I have wanted for a long time to produce a number of pigment
prints using well documented old methods and then see if X-ray diffraction
can easily determine which is which. I hope to get this work done in time
for my next carbon book possibly next year.
Luis Nadeau