There is a straight foreword standard test for determining how long writing has been on the paper. It's done by taking a small sample and determining how dried out is the ink by timing how long it takes to dissolve in solvent. It takes longer to dissolve the longer the writing has been on the paper and a short time if the writing is recent. Even years after the writing, the ink continues to dry out. Many forgeries have been identified using this method.
The other method involves identifying the specific chemicals and substances in the ink. That's the test that would be expensive.
Last edited by drcy; 02-11-2015 at 08:46 PM.
|