I hope that it is okay that I add something that isn’t really helpful here…
I am left-handed. When I sign or write something “important”, my letters are very upright and the penmanship is very controlled due to the position of my hand and pen. When I’m just writing a note or something similar, my letters do slant to the right and I hold the pen totally differently. However, although the two writing styles look nothing alike, I suppose the letters are similar in the different styles. (Over the years, I’ve noticed a few of my left-handed friends doing the same thing.)
Perhaps it’s just something that we have learned to do to cope in a somewhat right-handed world but I thought I would share my writing oddity in hope of it helping in the future.
Update: I just wrote an identical sentence using my two styles. Very few of the letters are similar in the two styles. An ‘a’ even looks like it was written by two different people. Only the ‘y’ is very similar. I wonder if other people would have the same results — I am quite surprised how different the letters look from the controlled upright writing to the more loose forward slanted writing.
