Hi. I have been this in a collection but struggling to work out if it is real or a preprint. When held to light it looks different to photo and stands out. What the easiest and guaranteed way to be sure?
This preprint appears to be on two different photographs. Your last photo was a good attempt - the ink, if live, should look orange or other in the glare of a light. That does not preclude an Autopen though there are ways to spot those as well.