Kaleea -

There was no whiteout then, but every scribe - of necessity - had a good "quill knife" for sharpening and reshaping the goose feather; and most such knives worked quite nicely for "scratching off" an ink error. Properly done, the removal can be much less visible, and with less damage to the parchment/paper, than when attempted with an "eraser" (which didn't come along until much later).

The technique survived, in certain circumstances, into the archaic era cited above.

John