1. Create a text block with several lines of text.
2. Change the first character(s) in each line to various sizes.
Look at the left alignment of the first character in each line of text. The first letters may not be left-aligned perfectly. (The discrepancy might be so small, you need to zoom in to notice.)
This is because the character definitions include white space to the left of the character (the character widths defined in the fonts are wider than the actual characters and include some leading white space). Larger font sizes will have more leading white space than smaller sizes. Thus, if the first character in a line of text is a larger font size, the line may appear to be shifted to the right by a very small amount. This may occur with some fonts more than other fonts. Also, some TrueType fonts may be off more than their Postscript equivalents.