What kind of "error-correcting artifact" product did Betty naismith gleim invent?

Before the invention of word processor, people could only write mistakes by circling or rewriting again and again, which not only wasted time, but also made writing look unsmooth and unsightly.

195 1 American secretary Betty? Naismith? Gleim invented the correction fluid. It uses a white opaque pigment and spreads it on paper to cover up typos. When the paint dries, it can be rewritten in its original position.

Because most manuscripts and letters are written on white paper, this pigment can cover up the traces of modification, which is not only more convenient for typing or writing, but also more neat.

At that time, the correction fluid was packaged in a small bottle, and a small brush or a triangular foam plastic was attached to the bottle cap for smearing.