The author was retained by counsel to determine whether a short, undated note was typed on a defendant's machine and, if so, whether it was typed in late spring or early summer 1984. Two other undated notes were also submitted for the same determination, but they were considered to be of less importance than the first note. Circumstances in the case indicated that the three notes could only have been typed during the period between January 1984 and October 1985, if they had in fact been typed on the suspect machine. The author first determined that all three notes had been typed on the defendant's typewriter, probably by the defendant. He then looked for the existence of slight slant variations in the common vertical letters t, l, and f, all of which were present in the three notes. Access was obtained to more than 40 documents which could be proved by examination and testimony of the defendant to have been typed by him on the typewriter in question. Of this total, 14 were selected to examine the slant of t, l, and f characters. Slant ratios of the three notes demonstrated little variability and appeared to place the notes in the spring/summer 1985 timeframe, not spring/summer 1984. The t was the most frequently occurring letter, and it also evidenced the most internally consistent trend over time. It is concluded that variations in typescript slant can be used to age-date documents within rather precise time periods. 9 references, 3 tables, 1 figure.