“Helvetica Placed on Arial (in Illustrator)” is a typeface that comes in two styles: Minus Front and Minus Back. Minus Front subtracts Helvetica from Arial (in Illustrator) and Minus Back subtracts Arial from Helvetica (in Illustrator).

Below are the steps used for designing this typeface:
1- Set the entire glyph set in 50 pt Helvetica in Illustrator.
2- Set the same glyph set also in 50 pt Arial in Illustrator.
3- Place Helvetica glyph set on Arial Glyph set.
4- Expand both glyph sets.
5- Ungroup both glyph sets.
6- For each glyph, center align the Helvetica and the Arial versions both horizontally and vertically.
7- For achieving “Helvetica Placed on Arial (in Illustrator), Minus Front,” execute the minus front pathfinder tool for all of the glyphs. This will subtract Helvetica from Arial.
8- Repeat the steps 1-6 on a new artboard.
9- For achieving “Helvetica Placed on Arial (in Illustrator), Minus Back,” execute the minus back pathfinder tool for all of the glyphs. This will subtract Arial from Helvetica.