The differences between Retina Normal Bold and Retina Microplus Bold are minimal but intentional. The lines are different in Microplus, as they seem to bend slightly at the intersecting forms, allowing for more space between the lines (which makes legibility better). Instead of directly straight line intersecting with the bowls of the d and b, for example, there is a more exaggerated "v" at the base of the bowls, cutting into the letterforms . The "v" shape is mimicked on the inside of the stem. Creating slanted lines to allow the most open white space possible in a small typeface, as opposed to straight, even weights in the Normal Bold, allows the typeface to be read best at a small point size.