\documentclass{article}

\begin{document}
This one had align = bottom $G$ but this one align = middle $S_{G}$ since it
has a descender. The padding is correct.

ALIGN=MIDDLE makes the MIDDLE of the image align with the baseline of the text.
Some browsers may align the MIDDLE of the image with the middle of the text, which is
not correct.

\end{document}
