2.6 Font Hierarchies
We recommend a carefully chosen ratio for sizing type for information hierarchies (head, sub-head, body text, etc.) so there is a logical relationship between small, regular and large. Ratio is ideally between 1.2 and 1.5 scaling factors. The base value of the font size is critical as was discussed in section 1.2 Font Size. Too small a base value will lead to information hierarchies too small to comprehend when the screen is reduced and too large when the screen is enlarged. Especially when scaling up the layout can become seriously malformed, incomprehensible word breaks may occur, text in frames will become truncated and overflow in confusing new pages, and text in buttons may disappear behind frames, etc. It is strongly recommended that designers base their page design on scaling and attempt to control their layouts so that the hierarchy, reading order and navigation do not become compromised when scaled to at least 150%.