The thing is that many sans-serif typefaces are usually intended for universal usage. But sometimes faces that work fine in body text look not so good in large point sizes for display purposes when all the contrast in non-contrast sans-serif, or ink traps, become visible to the naked eye. 

Every designer solves this problem in his own way. We offer a drastic solution in our Stem: a sans-serif with optical sizing. The first part of the type family, Stem Display, is for use in largest point sizes, from 36 pt indefinitely. Stem Display consists of 12 faces of widths from Hairline to Bold, and it has true italics. The development of Stem type family will include Stem Text for body text and “traditional”, universal use, and Stem Caption for small point sizes.