Indented Writing Restoration

If a document is written while resting atop other papers, impressions of the writing will be transferred to the underlying sheets. If heavy pen pressure has been used, indentations are often seen when the document is illuminated with side-lighting. A more sensitive technique is required to view indented impressions produced by normal or light pen pressure. 

Figure 1
The Electrostatic Detection Apparatus (ESDA) is a special instrument capable of restoring handwritten impressions in paper that are completely invisible to the naked eye. 

The document to be tested is placed on the instrument and covered with a sheet of transparent film. The film and sandwiched document are then given a strong electrostatic charge (see Figure 1). The charge dissipates quickly except in those areas where indentations occur. The final step involves applying black toner to the surface of the film which adheres to the charged areas rendering the indented writing visible.

The examination of documents for indented handwritten impressions can be important for many reasons. This technique can produce a record of information from papers that have been lost, destroyed or are no longer accessible.  In Figure 2, indented impressions have been restored on the top sheet of a pad of paper. Although nothing was visible on the tested sheet, the ESDA restored writing on a page that was removed from the pad earlier.

Figure 2


Relative Sequence of Written Entries

ESDA test results can also reveal if a questioned entry was written before or after other information on a document. This can be very important when examining patient medical records, notebooks, diaries, journals or agendas where entries are suspected of being added some time later. In Figure 3 below, the sentence outlined in red was allegedly written on July 22nd, the same date the entries above and below were made. The questioned entry superimposes with writing in the second line of the box dated July 29th on the following page in the journal (see Figure 4).

Figure 3

Figure 4


Figure 5

The July 29th page of the diary was tested for indented writing impressions using the ESDA. The results appear in Figure 5.

Indented impressions originating from writing in the July 22nd box appear black while visible writing on the July 29th page appears white against a grey backgound.
Examination of regions where the black and white impressions intersect indicate the relative sequence of entires on the two pages. Figures 5-A and 5-B below are enlargements of rectangular areas A and B shown in Figure 5.

Figure 5-A

Figure 5-B

White lines of the word "Take" in Figure 5-A are unbroken and appear to lie over the black writing corresponding to impressions from the preceding page.

This provides proof that the first line of the July 29th entry was made after the first line of the July 22nd diary entry. This sequence agrees with the respective dates of the two entries.
Unbroken black lines in Figure 5-B indicate the questioned entry in the July 22nd box was made after the second line in the July 29th box of the diary.

Contrary to what is suggested by their respective dates,  the handwritten notation, "Bought 2 antique gold watches for $6750.00." was added sometime after the second entry in the July 29th box.