Overstrike

With the wide adoption of Unicode (especially UTF-8, which supports a much larger number of characters in different writing systems), this technique is of little use today.

[3] The horizontal offset is essential since, unlike a typewriter where repeating a letter in exactly the same space will make it darker, most modern printers will not darken repeated "strikes" to the same space.

Actual bold fonts are designed with some features thicker and others the same size as a regular font, so the use of this "fake bold" is considered undesirable from a typographic point of view.

[citation needed] Overstriking with an offset was also used to created "Blackboard bold" style characters used in mathematics.

[8] No known keyboard arrangement includes a function key that allows any two characters to be superimposed.