Rotary engravers are recommended for producing tactile characters because you need to use a beveled bit to cut out the raised characters, so the top surface is thinner than the base. Only rotary engravers can take care of beveled-edge cutouts. Try running your fingers quickly over a set of laser-cut characters and you’ll see why people who read by touch prefer the beveled characters.
Reading raised characters or Braille requires that the signs themselves follow a huge number of complicated and detailed rules with often-tiny measurements. Otherwise, the signs can be unreadable and useless.
Characters meant for touch readers need at least a slight bevel on the characters, which must be a minimum of 1/32-inch raised. Stick to that – anything higher or lower is difficult to read.