# How to control the horizontal location of subscript?

Sometimes I find the subscript is located too far from the letter (to which it is the subscript) such as in

\mathbf{v_{_\text{B}}}


How to get the subcript closer to the letter?

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Try \mathbf{v_{\mkern-4mu_\text{B}}}. However, are you interested in a general solution? – Werner Feb 28 '13 at 8:04
May be related is it possible to change the depth of subscripts? – texenthusiast Feb 28 '13 at 8:10
(1) B in your example doesn't seem to be "text", but rather "math symbol to be typeset non-slanted", therefore you might want to use \mathup{B} or \mathrm{B} in place of \text{B}. (2) Is there any specific reason why you want to do double subscript \mathbf{v}_{_\mathrm{B}} instead of simple \mathbf{v}_{\mathrm{B}} ? – yo' Feb 28 '13 at 8:35
That's a very odd markup, when would you ever want _{_ that is a subscript consisting of an empty base with a subsubscript? – David Carlisle Feb 28 '13 at 9:39

Reducing the size of the subscript is not the right solution, in my opinion. And \text is not the correct command to use, because it doesn't ensure an upright font, for instance in the statement of a theorem printed in italics.

A "double subscript" is definitely not the best way to reduce the size, in any case.

If you really need to push a bit down the subscript, add an empty superscript.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
$\mathbf{v}^{}_\textnormal{B}$ is good

$\mathbf{v}_{\scriptscriptstyle\textnormal{B}}$ is not so good

$\mathbf{v_{_\text{B}}}$ is bad
\end{document}


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Another way to get smaller caps is $$x_\textnormal{\scshape b}$$. – Andrew Swann Feb 28 '13 at 10:45
To be honest, I understand the OP's desire to make the B smaller. In the "good" version, the subscript B looks as big as the v. – Hendrik Vogt Feb 28 '13 at 11:40
@HendrikVogt I don't; if it's an uppercase B, so be it. – egreg Feb 28 '13 at 11:52