ENCAUSTIC PASTE.
The value of an encaustic paste in improving the effect of photographic
prints has become very generally recognised amongst photographers.
A good encaustic confers three special benefits on the print: it
gives depth, richness, and transparency to the shadows; it renders
apparent delicate detail in the lights which would otherwise remain
imperceptible; and it aids in protecting the surface, and so tends to
permanency. One of the writers has in his possession prints that were
treated with an encaustic paste thirteen years ago, which retain all
their original freshness and purity, while prints done at the same time
from the same negatives have gone, to say the least of it, "off colour."
Various formulæ for the preparation of encaustic pastes have been
published, and many of them very excellent. The qualities required are,
easiness of application, and the capacity of giving richness and depth
without too much gloss, and of yielding a hard, firm, permanent surface.
For a proper combination of all these qualities, nothing has ever
approached the paste of the late Adam-Salomon, of which the following is
the formula:--
Pure white wax 500 grains
Gum elemi 10 "
Benzole 200 "
Essence of lavender 300 "
Oil of spike 15 "
The wax is cut into shreds, and melted in a capsule over a water
bath. Placing it in a jar, and the latter in a pan of hot water, will
serve. Powder the elemi, and dissolve it in the solvent, using gentle
heat. Some samples of elemi are soft and tough, and will not admit of
powdering, in which case it may be roughly divided into small portions,
and placed in a bottle with the solvents. Strain through muslin, and add
the clear solution to the melted wax, and stir well. It is then poured
into a wide-mouthed bottle, and allowed to cool.
The encaustic paste is put on the prints in patches, and then rubbed
with a light, quick motion, with a piece of flannel, until a firm, fine
surface is obtained.
We give another simple formula which is efficient, though we ourselves
prefer the above.
White wax cut into shreds 1 ounce
Turpentine 1 "
and thinned down, if necessary, till it has the consistency of "cold
cream."
Yet another is--
White wax 1 ounce
Benzole 2 ounces.