One of two postings that were sent on Friday, but which have only just
(Sunday night) been reported undelivered.
Found this in Henley while looking for info on luminous prints.
PAPER NEGATIVES.
There are a few simple steps in this control method: 1st, the making of a
print, either by contact or projection, of the size desired in the finished
print. (Negatives smaller than the finished print size are projected in the
enlarger.) Corrective work, with pencils, crayon and/or chalk, as well as
chemical reduction of dense areas, is done on this paper positive, (usually
called a "diapositive"). This diapositive is on very light-weight paper,
enabling, after completion of the corrections, a print to be made by
contact on another light-weight paper. This resulting second print is now a
negative on paper and some corrective work may also be done on this. The
final print is made from this paper negative, the selection of the final
paper usually being one of a. so-called "artistic" surface that will fit the
type of subject matter.
The use of intermediate positive and negative made on paper, naturally
results in a finished print showing a certain amount of the paper texture or
grain. Two major methods of making paper negative prints are in general use,
one emphasizing the paper grain so as to add to the final effect and one
method minimizing this grain. The paper negative process is especially
suitable for broad effects, pictures in which delicate, minute detail is
relatively unimportant. It is also one of the easiest of the control
methods. The difference in the grain quality is simply a matter of
manipulation. The ordinary method, (giving the most grain) is described
first. The methods of working and formulas used, are.the same for either the
grainy or subdued grain methods. The only difference is in the position of
the emulsion side of the paper during the various steps.
Any enlarger may be used, any good quality negative is suitable. The
negative should preferably be somewhat on the thin side, possessing good
detail in both shadows and highlights as well as a generous scale of tone.
It is inserted into the enlarger in the regular way and an exposure made on
very thin or light-weight enlarging paper, held in the easel as when making
a straight enlargement. The paper should be of the long-scale or "soft" type
since the paper negative process gains contrast. Exposure of the diapositive
should be rather full and development kept short. The result should be a
very soft print, having no really brilliant whites or deep blacks, having
soft gradations of tone. Dark areas may now be worked on, lightening them up
with the regular print reducer solutions. A quick reducer is an adaption of
the "Farmers," a few crystals of potassium ferricyanide in a weak solution
of ordinary hypo and water. The reducer should be slow in action since too
rapid a reduction will result in hard, sharp edges instead of soft blended
ones. Work is done on the wet print, frequent rinsing with water being done
while the reduction work is used. This enables observation of the progress
of reduction. When the desired changes have been made in-so-far as
lightening up areas are concerned the print is dried and then work is done
on both the back and front of the print with soft lead pencils. Spots and
mechanical errors are removed and areas that are too light are darkened by
means of graphite or chalk. All this work is done by means of transmitted
light, the diapositive being supported on a sheet of glass and having a
strong, evenly diffused light passing through it. Other lights in the room
should be extinguished, it is necessary to judge the progress of the work by
the transmitted light only.
There are no special formulas for developing this diapositive, the regular
paper developer to which one is accustomed is all right, except that it can
be diluted more than would generally be normal in order to maintain the
necessary softness in the diapositive.
When the alterations and handwork have been completed on the diapositive it
is then ready for printing, by contact, on another piece of the same type of
paper. (It is easy to remember that whatever is lightened or darkened in the
diapositive will be correspondingly lightened or darkened in the finished
print. The paper negative is made and developed in the same type of
developer as the diapositive. This paper negative should also be somewhat
on the soft side, full exposure and short development aiding in this. When
dry, additional handwork is done on back or front or both, until tones are
altered or objects eliminated to suit. It must be remembered that, unlike
the diapositive, any areas lightened in the negative will be darkened in the
finished print. From the completed negative, a final print is made, by
contact, on the chosen paper, this paper being handled as when making a
print from a regular negative. The paper diapositive and the paper negative
may be oiled or made transparent in order to reduce printing times which,
of necessity, will be longer than when printing from a film negative.
Contrary to belief, this transparentizing emphasizes the paper grain more
than if it is not used. It is to be noticed that the various mediums,
negatives and positives, are printing with the emulsion side to emulsion
side in each step.
The following will make paper transpar-ent
1. Alcohol, 6 ounces; Castor Oil 1 ounce.
2. Paraffin, 4 ounces; linseed oil, 1 ounce. Use at 176 deg. F. and after
immersion dry the print between blotting paper.
3. Mineral oil, (white), 5 parts; Alcohol, 1 part.
4. Rub in white vaseline on the wrong side of the print, using a clean rag.
Allow to stand for some time.
In using any solutions to transparentize paper care must be taken that the
medium used for this purpose does not stain the paper used for the next
step.
If difficulty is experienced in having ex-posures too long or paper grain is
too objectionable a regular, soft gradation film emulsion may be used for
the diapositive. There is a limitation to the ease with which control work
may be done on this film positive, in the hands of the less expert.
However, the use of a film positive has advantages over the paper positive
in many respects.
If less paper grain appearance is desired in the finished print the
intermediate steps are as follows. Make the first diapositive with the back
of the paper uppermost, that is, print or enlarge through the paper stock
itself. After the work on this diapositive is completed (being done as
previously mentioned), the paper negative is also made with the back of the
paper against the emulsion side of the diapositive. Thus the grain of the
paper in each case will cancel out the grain of the other and this method
gives the least grain. Intermediate grain is secured by making only the
diapositive through the back of the paper, reversing the negative in the
carrier in order to bring the objects right side to.
Liam
This archive was generated by hypermail 2b29 : Tue Jan 11 2000 - 12:10:49