This document discusses type and font readability and relationships. It provides guidelines for using type effectively, including: 1) Readability is the most important purpose of type, allowing easy reading and understanding of text. Factors like size, color and font can contribute or distract from readability. 2) Using one consistent type family with little variation is called "concordant" and communicates formality but can be dull. Mixing similar but different typefaces is "conflicting" and less interesting. Using distinct, different typefaces is "contrasting" and makes for the best designs. 3) There are categories of type including oldstyle, modern, slab serif, sans serif, script