and inverting the ivory to cut the sides of the lower half of any oval.
No cutting across the grain should be attempted by an inexpert person.*
the ivory set into the frame, a proper backing becomes necessary to
hold it in its place. For this a piece of aluminum cut to fit the frame
is the most serviceable of light metals. By laying a piece of very thin
paper, larger than the frame, across the back, and pressing the
aluminum back-plate into the bezel, a firm hold is assured. Square or
oblong ivories are best secured by dispensing with the mat, placing a
sheet of good quality mica behind the paper backing and sealing the
edges with gold-beater's skin (so-called "skin-plaster"). The use of
photographer's slide binder is also entirely safe. The sealing should
be perfect, to prevent the imperceptible moisture of damp weather
finding its way under the glass. Experience has shown us that while an
ivory will not deteriorate on account of moisture, the inside of the
glass covering will in time show fogginess, though not in so great a
degree as do daguerreotypes, where the glass and the metal are more
active in collecting a chemical deposit under the glass.
CARE OF PAINTINGS ON IVORY
above final remarks remind us that an ivory painting should not be
exposed to sudden changes of temperature. A cold piece of glass will
immediately attract and condense any latent moisture. It will draw it
in under the framing and will hold this moisture for many days.
Sunlight would bleach most colours more or less, no matter what make
and whether they be oil colours or pastels, let alone water-colours of
delicate, pellucid gradation, with practically no body strength.
Miniatures kept in the ordinary light of our homes will last
indefinitely. There is nothing in their
*A11 thick ivory is best cut with a jeweller's saw.