# Looking for a blackboard bold (\mathbb) math font that is thicker than Latin Modern or Computer Modern

I am trying to find a blackboard bold math font that satisfies the following two conditions:

1. It looks similar to Latin Modern or Computer Modern, but thicker.
2. The space between the main character and its superscript of this font is as small as (or smaller to) the one of Latin Modern or Computer Modern.

The reason behind this is that I'm using the STIX Two font in XeLaTeX that requires the unicode-math package:

% STIX Two font
\usepackage[math-style=ISO]{unicode-math}
\usepackage{xltxtra}
\setmainfont{STIX2Text}[
Extension       = .otf,
UprightFont     = *-Regular,
ItalicFont      = *-Italic,
BoldFont        = *-Bold,
BoldItalicFont  = *-BoldItalic ]

\setmathfont{STIX2Math.otf}


And the blackboard bold symbols of this package are just ugly to my taste. I can use Latin Modern's ones instead:

\let\mathbb\relax
\DeclareMathAlphabet{\mathbbb}{U}{msb}{m}{n}


but the symbols look too thin compared to the rest.

An alternative is using TeX Gyre fonts, e.g.:

\setmathfont[range={\mathbb}]{TeX Gyre Termes Math}


but then I found that the space between the main character and its superscript is very large, which is also ugly.

Here's a comparison:

Could anybody suggest me with a font that satisfy the above two conditions?

If you like TeX Gyre Termes Math and don't expect to need a large number of different superscripts, you could just add a kern to move the superscript, like one of the arrangements below.

   \documentclass{article}
\usepackage[math-style=TeX, bold-style=TeX]{unicode-math}

\setmainfont[]{STIX Two Text}
\setmathfont{STIX Two Math}
\setmathfont[range=bb]{Tex Gyre Termes Math}

\usepackage{xparse}
\DeclareDocumentCommand{\RN}{m O{-0.08}}{\mathbb{R}^{\kern#2em #1}}

\newcommand*{\Rn}[1]{\mathbb{R}^{\kern-0.08em #1}}

\begin{document}

$\Rn{n_i}$

$\RN{n_i}$

$\mathbb{R}^{\kern-0.08em n_i}$

$\RN{n_i}[0.0]$

\end{document}


Found a perfect one:

\setmathfont[range={\mathbb}]{Cambria Math}