The Blackwing, like almost all writing instruments, are considered to be right-handed. This is to say that the writing on the pencil is correctly positioned when it is being held in one’s right hand.
A small number of Blackwing pencils were left-handed.
Some Blackwing pencils were printed with the text left-handed, so that when held in your left hand the text would be legible. It’s not been made 100% clear whether these were mistakenly made or purposely done, but they do exist.
If these were a mistake it’s clear what happened: the pencils were sent to the ferrule machine backwards, so that the metal ferrule (the eraser holder) was put on the bottom of the wooden pencil instead of the top.
We can be fairly certain that these were mistakenly made because the printing is pushed forward, so much so that it would start to disappear with just one or two sharpening of the pencil. If these left-handed pencils were made on purpose, we’d expect the printing to be left-aligned, or put at the top of the pencil, close to the ferrule.