Kerning:
http://paraleaglenm.wordpress.com/2011/05/10/debunking-birth-certificate-forgery-claims/
“The final ’ty’ was typed with index fingers of the left and right hand in a quick succession, straining the spring tension indexing of the platen . . . recreating the expert’s ‘kerning’ in a mechanical typewriter . . . something he said was impossible. Using ‘hunt & peck’ fingers instead of touch-typing created an exaggerated ‘kerning’ effect of 4 pixels overlapping.”
I recall that the libs initially had a different reason for all the LFBC anomalies and even the layers. They said they were the effects of OCR and that it explained everything. That explanation didn’t fly.
This one doesn’t either.