Study documents Kiev Ukraine. Investigation of intersecting ink strokes. The sections of the intersection of the strokes were studied by us under the MBS-10 microscope without light filters and with light filters, microscopic examination of the visible and infrared luminescence pattern was carried out, the wet contact copying method was applied.
During the experiments, the most common types of ink were used: blue, violet, black, red, made on the basis of basic and acid dyes.
A microscopic study of intersecting ink strokes was carried out at a magnification of 16-32. The best results were obtained by observing in oblique light, since illumination by a narrow beam of light emphasizes the structure of the strokes.
The degree of illumination should be changed depending on the brightness of the strokes. The strokes must be viewed along their entire length, each under different lighting conditions. The greater the length of the intersection of strokes, the better the conditions for their observation.
Study documents Kiev Ukraine. At microscopic research it is possible to reveal the signs allowing to judge about sequence of drawing of intersecting ink strokes:
- A) the removal of the colored fibers of the paper from the lower stroke to the upper one;
- B) the presence of a continuous trace from the pen – a sign of the top stroke; If one of the strokes is made with a pen with a sharp pen and the other with a pen with a bent tip, the picture may be false;
- C) the ink blurs of the top line on the bottom line;
- D) the “spreading” of the ink of the lower stroke along the top is often observed when writing with a curved tip on well-sized paper, while the amount of the dye of the lower stroke at the intersection sharply decreases. With a slight magnification (for example 16x), the top bar appears to be continuous. “Blurring” the bottom stroke along the top should be distinguished from the spread of the top line on the bottom, because incorrectly evaluating the characteristic, you can make an erroneous conclusion;
- E) the dye of the top stroke at the intersection point and in the nearby areas loses a bright color, as a result of which the bottom stroke comes to the fore (well visible), and the upper one is interrupted some distance from the lower one. Where the upper stroke turns pale, near the intersection point one can often see the weak “dilutions” of the dye of the lower stroke;
- F) the stratification of the upper stroke on the lower one and its continuity are often observed when strokes are executed with a stylus tip on well-sized paper.
The longer the interval in the execution of intersecting strokes, the better the layering of the top line on the bottom line and its continuity.
Described in pp. “A”, “c”, “d” signs are quite convincing. The detection of one of them during a microscopic examination of the intersection of the ink strokes allows one to draw a conclusion about the sequence of their application, without resorting to other methods of investigation. If, on microscopic examination, the signs listed in paragraphs “B”, “d”, “e”, the conclusion should be confirmed by the results of studies using other methods, since under certain conditions a false effect may not be excluded.
In order to detect the spreading and entrainment of paper fibers or dye particles, it is possible to investigate the intersection points in the spectral region in which the dye stains (or colored paper fibers) differ significantly in brightness. For illustration, it is advisable to choose an area in which the blur will look dark against a background of a more transparent stroke. However, in the absence of blurs, increasing only the brightness contrast can distort the picture and cause a false effect.
We investigated slightly intersecting ink strokes that were slightly different in color, when microscopic examination of which (microscope MBS-2, magnification 16-56x) without light filters failed to reveal signs that indicate the chronological sequence of their implementation.
In order to identify the spectral zones, in the study in which color contrast could be enhanced, we studied the reflection spectra of ink (standard and reduced concentration of dyes). The ink was applied to the paper in the form of colored areas measuring 3.5X3.5 cm. Spectra in the visible zone were recorded using a spectrophotometer SF-10. The effective zone was chosen so that it does not include those regions in which the reflection of the compared strokes is approximately the same.
Analyzing the results obtained with microscope studies using light filters, we can conclude that a microscopic study of intersecting ink strokes with the use of light filters does not lead in most cases to the desired results. Of all the possible cases of intersections with this method, the best results were obtained by examining the intersecting strokes made with red ink for the “Rainbow” pens and red ink produced on the eosin. The signs that indicate the sequence of application of intersecting strokes become more pronounced when using the 3C-7 and 3C-3 light filters.
Study documents Kiev Ukraine. We work according to the legislation of Ukraine and guidelines.