This type of problem can even occur using type from the same family but slight variations in size. For example, if one line is 48 points and another line is 45 points, the slight difference in size looks accidental. Are they supposed to be different? If so, what does the difference mean? You can prevent confusion by making sure that the type for various levels of meaning (heads, subheads, and body text) are markedly different in size, weight, style, family, and so forth.
