Light stability of painted and stained wooden architectural toys

Our museum has been asked to lend 2 wooden architectural toys for an
exhibition that is to last an entire year.

One toy is a contemporary set of "Skyline" building blocks made in
West Germany.  The blocks have a natural wood finish and have opaque
bright red, blue and green windows.  The set also contains wooden
figures and trees which have bright red, yellow, blue, and green and
dark green finishes. This colour is translucent enough for the wood
grain to show through fairly clearly.  Since this toy is brand new
it is in perfect condition. Is there any way to predict the light
stability of the colours without concrete information on the type of
colorant?  (I will try to contact the manufacturer, "Haba", but I
don't know if I'll succeed in getting an answer before I need to
make may decision.  We are also suggesting that the borrower simply
buy a toy of their own, which would solve our problem.)

The second toy is a unique set of "Sky-Hy Building Blocks" which
dates from the 1920's and was made in Albany, New York.  It consists
of embossed wooden blocks and tiles.  The blocks are painted medium
green, light green and black, and have a yellowed varnish-type
coating on some faces.  The colour of these blocks is still fairly
fresh.  The wooden tiles, on the contrary, have already suffered
light damage.  They appear to have been stained light green with no
protective finish.  Many of them have already faded to a yellowish
tone with barely a hint of green.  Others remain fairly green on one
side but have faded quite a lot on the other.  There are enough
blocks to divide the set in half so that the borrower could build a
small building, show it for half a year, and then duplicate the
building with the other half of the set for the remaining six
months--but not enough blocks to make more subsets for more shorter
exhibition periods.  This toy was already exhibited for a few months
here at 50 lux 2 or three years ago.

The older toy does not look like a good candidate for an exhibition
of any length--especially for such a long show.  The new toy
inspires confidence because it is so bright and fresh-looking--but
of course it's present appearance really tells me nothing.  I would
appreciate hearing from anyone who has information on the light
stability of colorants that may have been used in the manufacture of
these toys or toys of these periods, or anyone with advice or
opinions to offer on the exhibition of such toys.

Karen Potje
Head, Conservation/Preservation
Canadian Centre for Architecture
Montreal, Quebec

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                  Conservation DistList Instance 10:52
                Distributed: Wednesday, December 4, 1996
                       Message Id: cdl-10-52-013
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