طريقة استعمال أفلام الليثو .. مجلة فن التصوير اللبنانية _ ع٤٣

**Ali Abbass** · 05-11-2023, 12:43 PM

How to use litho films

Litho simply means removing the areas of the color gradient that we want completely removed from the image, but there are other methods that are done by merging the different negatives of litho to obtain overlapping effects and creations that turn the image into a very important painting or poster.

People's admiration for the endorsement process of litho films (*) is due to the result that is obtained, as the colors in these images are limited to only two colors - dark black and pure white - which means removing all shades of gray completely, and this is the true or simplified meaning of litho works , which many consider just a removal of the color gradient. However, there is a whole series of additional effects that can be achieved by resorting to gradient separation (*) or label-making (*) techniques.

And when we move towards litho printing, the result will be to convert all the light areas into white and the dark areas into black, and the photographer controls the point at which the division will occur by controlling the exposure.

With the exposure of the litho film for a shorter period - or for a longer period - it is possible to determine the split point, at which the intermediate color gradient turns black, and for example, when working on a face image, the short exposure will record the darkest parts in the eyes and nostrils And the mouth only, and this will be printed as black. As for a moderate exposure, it will give a result with more details - it is very possible for the gray tones to come as a soft, delicate point, giving an effect in which there is some formation. As for the long exposure, it will capture all the shadows.
Printing process Here we will get a dark mysterious image. Only the brightest parts of the original will be printed as white.

In such a case, while litho positives are made from a continuous hue negative, the underexposed film is called a shadow positive, since only shadows and black areas will appear, and so an overexposed film becomes a brightening positive, so long as the areas Only the most glamorous will obey. Then we come to the standard exposure, and we find that it gives a medium-level negative. It is possible to touch each positive on Litho film to give the negatives a shadow, brightness, and a medium level.

It is also possible to make prints of almost all of the negatives or positives - although not all of them are likely to lead to very interesting results - as well as experimenting with exposures between the ones you have chosen, in order to reach a certain feature, this, and litho film can make distinctions Very subtle between gradations, either to include an intermediate color gradation area or to remove it entirely, by simply changing the exposure.

Experimenting with lithium:
When making litho negatives and positives, the most important stage in choosing the point at which the gradations will separate is the test clip, since it is how the negative appears with exposures that gives vital information about different exposures. The standard exposure of the litho film is that which gives completely black and pure white colors. Either with a preconception about this exposure. The litho chip can be exposed to a series of periods above and below it. For those who do not know what the standard exposure is, it is better to expose a test slide to a wide range of time periods, in an effort to achieve the most comprehensive sample among the mixed color gradations.
After completing the test slide exposure. It is endorsed as a regular slide and left to dry, and it must be viewed in daylight or in a well-lit room, as black colors appear as shaded darkness under a safety light. Then after you've finished choosing your exposure, the positives need to be made
As usual, but making sure to always use a fresh look with the correct time, otherwise the matter will lead to a degree of separation of the color gradient that differs from that in the test slide.

The final prints will show black and white gradations, but the exposure can be lowered on the bromide-sensitive paper as well, to get a gray and white print. This is still a two-tone print. However, it is possible to adjust the intensity of the gray colors so that the separation of the color gradient is preserved, but the effective light contrast decreases.
As with the use of negatives as originals in litho works, transparencies can be used
like that .
And to produce a positive black and white print only, it only takes one intermediate film, as long as we work from a positive at all. The first litho print is negative, and it can be used to print on paper directly, and by making another litho contact print, it produces a positive one that gives a negative effect on the paper.

In any case, as long as there is only one intermediate stage, the final print will always be reversed sideways when printing a sensitive layer on another sensitive layer. The simple remedy is to put transparency back to front in the enlarger while making an intermediate negative (*).

This is while the black and white negative of the orthochromatic litho or panchromatic film will give the same results, when printing from transparency we have added control over any red areas in the image, we point out here that the panchromatic film gives effects and produces all red areas as very light in the first print - negative - and dark Very in final paper edition or litho-positive.
Then by printing the litho negative - or positive - onto paper, we can reproduce the red areas in a photograph as either abnormally light or abnormally dark. This can create amazing unrealistic effects, with fake color gradations.
From a practical point of view, what we do, of course, on an orthochromatic film is to introduce filtering - filtering -
When working from transparency, the approach is the same as with negativity.
A test slide must be made to determine the cleavage point of the color gamut. When selecting transparencies to be used on an orthochromatic litho film, one must take into account that the more red the color in the subject. The more fake and unrealistic the end result. We will learn with increasing experience the quality of color mixtures that are most prepared for this type of treatment.
We point out here that the negatives made on ortho film are more pointy than those made on pan film, as long as the blue-sensitive layer records only one layer of the film instead of all three.

Multi color gradient printing
When we create a gradient separation, we turn a continuous gradient scale into just black and white. However, this same continuous scale can be divided into more than two hues. For example, we can make a print in which the shadows are black and the highlights are white and the midtones are an intermediate shade of gray. Indeed, there is theoretically no limit to the number of intermediates you can enter into a separation print of this color gradient, and the more intermediate tones you print, the more intermediate tones you print. The more the final result of a continuous color gradient image, but this will still be composed of discrete light gradations.

And the images you get create multiple color gradient separations, featuring a pleasing gradient quality. This is because the introduction of intermediate gray gradations produces a softer effect than that produced by a direct separation of two colors, but we are still able to adjust the effective light contrast by adjusting the shade of gray, and we also maintain control over what it includes in the image. And the emphasis we give on many different advantages.

Multiple gradient separations are made by printing a few litho negatives onto the same paper slide, one after the other. Each negative has different areas of black gradations, an example of this is that with the practice of exposure on three slides of Lilo, so that we reduce this exposure on one. And we do it correctly on the next, and exaggerate it on the third, so we will get from each of them a different positive in terms of The gradient when sublimated, one that will register only the deeper shadow areas as black, acts as a mask for a specific part of the print. At the end of the printing process, different parts of the print will have been exposed for different periods of time, and different shades of black or gray will appear.

And another will record the middle color gradations and shadows as black, and the third will be characterized by the presence of all black gradations except for the bright ones, and we can then touch all of these on Lilo until we make negatives for printing.

We then print the three negatives on a single sheet of paper to produce a separate color gradient image. In order to do this, all the negatives must apply to the paper subject to registration - that is, they must all be perfectly stacked - otherwise the image will not be clear, just as the edges of the color gradient areas will not fit one over the other properly.

**Ali Abbass** · 05-11-2023, 12:45 PM

The perforation method is best for this recording. Two or more holes are made near the edge of each film strip or sheet of paper. These holes correspond exactly to the pins on the base plate of the enlarger, to which the film will fit snugly. We can perforate the material concerned before the exposure, then sign it on the pins in the dark, and so the displayed image will fall in exactly the same place every time.
After completing the development of the litho negatives, we can print them successively on the same paper slide. As long as the pins confirm that a valid recording has occurred accurately. A good economical method is to stick an old film cut on top Extend one edge of each lino slice, and punch holes in this cut so that we can get the most out of the material involved and the value.
As for the simplest method of recording, it is to use a regular punching tool, which is used in offices, and a board with two pins located at the same distance as the two holes made by the punching machine, which you can make completely easily.
to stick it to the enlarger base plate but although this method is much more accurate it is also much more expensive nonetheless, and to do a lot of gradient separation work. The costs may be worth paying.

For a less expensive method, a good quality office punching machine, strong enough to punch holes in a plastic film slide without tearing or kinking, can be used. And where we will have to use this machine in the dark. It must be centered on a board, so that the film remains flat during this perforation, and we can make pins in wooden pegs, or cut the heads from thick pins, then file them smooth. The pins should be installed in a board larger than the largest piece of material that you are likely to use. It should be noted here that the photographic punching machine makes two holes of different shapes, which means that it is not possible to install the film from the wrong side in the dark, and there are groups of pins that we can stick to the base plate.

But before starting the processes involved in making multi-gradient separations, all the materials we need should be perforated in the dark and put back into light-proof boxes or envelopes. As for the orthochromatic film and paper, they can be perforated under a red safety light.
After we have finished choosing a negative for printing, we put it in the enlarger and display it on the base plate, leaving a wide margin for the recording holes. And after paving the picture. We place the staple bar close to the image and stick it in place there.

And now to make a test slide that allows choosing the color gradations that we want to print. We do not need to record the movie for the test slide. We also have to overexpose, as we do to separate a single color gradient. We reduce the slide and make a decision with the color gradations that produce the gradient differences that we want. As a general rule, exposure intervals should be chosen that produce the most prominent differences, and we can absolutely choose to make any number of negatives, but for the first chapter, it may be advisable to use only three.
We take a perforated lino film strip and sign it on the pins in the amplifier base plate. We scan it over one of the chosen time periods and then repeat with the next two slides giving the other two exposures. Now, we can successively and touch print each negative on one slide of plain bromide paper, giving each negative just enough exposure to produce a gradient of color. Medium gray on the sheet. Then we make a test print first to see what that exposure is. Illuminated, we stick a piece of bromide paper with the light of the dark room next to the recording rod that accommodates the pins and the sensitive layer to the top, then we put the first negative on the paper and its sensitive layer to the bottom. We make a test clip, and then we show the paper and examine it in the light.

You should stick another paper strip and place the first negative on the staples. Then we display the light and replace this with the negative of the second stage, then we repeat the process for the third, while adhering to the same exposure always, as well as paying attention to the contact print and the sensitive layer on the sensitive layer.
If we recorded each slide correctly and scanned correctly every time, the finished print should now appear in black and white and two intermediate shades of gray. If we use two negatives, we produce a single gray gradient; Using four negatives, we produce three shades of gray, and so on.

In addition to printing from three negatives, we can try different mixtures of negatives and positives of the shadow first, then print the negative of the middle color gradient, and sometimes when printing the negatives of a very wide accurate line, these and positives together, we produce effects caused by the dark areas in the negative because they are slightly different in terms of scale For the areas that parallel it in the positive, it is a condition that allows a little light leakage to form a very fine line on the paper.

This gradient separation process is actually a form of label making, and the simpler method of label printing can only produce similar gradations. This means that all images must be reduced to basic color gradations that can be placed on top of each other at that time. For label, or gradient separation, with the same appearance. As long as the gradual color gradations and colors were replaced by non-contrasting areas (*) with clear and distinct borders, we finally point out that making colored posters gives capabilities that exceed the capabilities of black and white, and once we master working with monochromatic, we can easily switch to colored work, which we will discuss later⏹

طريقة استعمال أفلام الليثو .. مجلة فن التصوير اللبنانية _ ع٤٣

طريقة استعمال أفلام الليثو .. مجلة فن التصوير اللبنانية _ ع٤٣

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