In Fig. 182, A and B represent a mask and counter-mask respectively, the latter being of slightly larger dimensions (from 1- in. to / in.) than the opening in the former, so that, when printed under a negative, a print is obtained with wide margins, which, with the exception of a thin white edge (about in. in width), will be of light or medium grey tone when exposed under the counter-mask.
For printing film negatives both the mask and counter-mask should be stuck in corresponding positions on pieces of glass slightly larger than the sensitive paper to be used ; the position of the latter is exactly determined by means of a " square " cut out of thin card and fixed along two sides of the glass to serve as a stop.
For printing from glass negatives the masks should be fixed in a cardboard frame the opening of which is cut slightly larger than the plate, and in which the latter can be fastened with gummed strips of paper, the gelatine surface of the negative being towards the mask, while the " square " edge serving as a stop for the paper is fixed on the other side.
Before such border-masks are mounted, the outlines of the picture and of each frame to be used should be drawn on a piece of stout paper. The attachment of the mask and counter-mask should be done by the aid of this ing, vignetted prints can only give pleasing results if the subject has been taken in front of a light uniform or cloudy background without well-defined patterns.
Vignette printing may be done either with a glass or celluloid vignetting mask, which, except for a central portion, is coloured orange-red, or by a series of cut-outs of translucent paper placed one over the other, the edge of each coming about in. behind the edge of the preceding piece. A zinc or flexible cardboard guide-piece, one of the outlines being made flush with the side of each piece, after the guide-piece has been thrust as far as it will go into the cut-out square.
Surrounds of several borders of different tones can be easily designed, and effects similar to those obtained by multiple mounting with superimposed papers thus obtained. Instead of a piece of plain glass fixed to the counter mask, it is possible to employ a negative reproducing the texture of a material such as coarse canvas. 1 Muslin or net can also be
stretched on the glass.
As an example of the various effects obtain able in this way, a combination of mask and counter-mask is shown in Fig. 182, which allows of a grey border being made at some distance from the picture which is printed under the mask A.
515. Vignetting. Leaving aside the case of vignettes with a dark background (so-called Russian vignettes) which are made under a counter-vignetting mask during a second print vignetting mask, with a finely-toothed or saw edged opening, may also be used, and lastly there are various types of home-made vignetters which are sometimes better suited to the shape of the Except when using a vignetter of ready-made gradation, vignetted prints should always be made in highly-diffused light, keeping the vignetter as far as possible from the negative, so as to produce a sufficiently large penumbral region (f in. at least for average-sized pictures). In nearly all cases it is further recommended that a piece of ground glass or other diffusing material be placed above the vignetter.
Special care should be taken to ensure a per fectly diffused light when vignetting prints on developing papers. Failing this, instead of directing the frame towards the source of light, it may be turned towards a large white surface illuminated as uniformly as possible by one or more lamps, the direct rays of which are unable to reach the frame.
The simplest method of preparing a vignetting mask is to cut in a piece of cardboard an opening of slightly smaller dimensions than the portion of the negative to be retained. The opening is covered with a piece of translucent paper on which the outline of the unprotected part is lightly pencilled. Excellent results will be obtained if this mask is placed about i in. from the Another method is as follows : A counter-mask placed on a very uniformly illuminated opal or ground glass plate is photo graphed purposely well out of focus. The resulting negative will form a vignette of variable diffusion, which can be varnished or bound up with a piece of plain glass so as to prevent the gelatine surface becoming scratched.