From the Speckin Forensics FAQ Archive – Is it possible to determine when a questioned document was produced?

Handwriting and Forgery Examination Speckin Forensics

Yes, through several different methods that can be conducted in our laboratory.
Some Methods Dating for Handwritten documents
1) Dating of the ink
2) Dating of the paper
3) Impressions found and sequencing of writing with impressions

Some Methods for Dating Photocopied documents
1) By comparing the unique photocopy damage pattern that changes over time, to a series of documents of unquestioned date from the same office.
2) Comparison of the toner used as in the same manner above, noting the time frames that toners matching the questioned document were used.

Some Methods for Dating Computer Generated documents
1) Examination of the computer and hard drives that created the document.
2) Toner analysis as described above for copiers.
3) Damage patterns that may exist from the printer, commonly seen in inkjet printers.
4) The type of paper used and any associated watermarks.