Graphing is still necessary for the blind, but it’s more common to use a plastic sheet on a hard rubber clipboard with a stylus that causes the plastic to rise up when it’s pressed with a bit of force. (Though while googling for it I found plenty of examples like yours so maybe less common than I thought)
The paper was in with a bunch of braille GED study books. One might need to do some graphing to get one’s GED.
Graphing is still necessary for the blind, but it’s more common to use a plastic sheet on a hard rubber clipboard with a stylus that causes the plastic to rise up when it’s pressed with a bit of force. (Though while googling for it I found plenty of examples like yours so maybe less common than I thought)
https://www.aph.org/product/tactile-drawing-film/