Glass spheres on painting

Janine Wardius <janine [at] kunstmuseene__no> writes

>I am treating an early 20th century oil-type painting on canvas
>which the artist decorated by adhering small half spheres of colored
>glass to the surface (several colors, and 3 sizes, 17 mm, 9 mm, and
>6 mm diameter). Some of the half spheres are lost, and the curator
>prefers me to replace them with something that looks the same (just
>inpainting is not an option). I can imagine casting replacements by
>adding color to a clear resin, perhaps epoxy of some sort. Does
>anyone know of a casting material that looks like glass and won't
>noticeably discolor over time? If so, how would you recommend adding
>transparent color to it? If not, are there any other suggestions for
>how to replace the spheres? I'm afraid it could be hard to match the
>colors well enough by ordering glass spheres ready-made.

If you go online there are literally thousands of clear casting
resins advertised, which usually come with their own tints. Epoxies
seem to be a good possibility, one could also use polyester resin or
PUR resin. If there are no transparent tints available it may be a
possibility to cast a clear half ball and to just in-paint the
underside of the half ball or the painting surface before adhering
the half ball. There are also a large number of companies where one
can order pre-cast glass balls in almost any size and color. Maybe
one can get sample colors from the manufacturers. If the colors
would not work,, I would try to color the underside of the glass
ball or the paint layer as mentioned above.

Bettina Landgrebe, conservator
The Chinati Foundation
1 Cavalry Row
PO Box 1135
Marfa, TX 79843
432-729-4742
Fax: 432-729-4597


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                  Conservation DistList Instance 25:47
                  Distributed: Friday, April 20, 2012
                       Message Id: cdl-25-47-004
                                  ***