FLUIDO is a variable font, which has got four axes: the Weight, the Contrast, the Serif and the Italic. So this font can transform from sans (or grotesque) to serif (or antiqua) without using plus alternate versions of the character. Also it can transform to slant and contrasted instances. Moreover the slanted states of the antiqua instance's (contrast+serif+italic axis combination) lowercase letters change to real italic characters. Thus, from grotesque to antiqua, a lot of font styles can be created from a single font file.