unicode-math: Double-struck math fonts

Mplus gets close:

Note: Barbara is right.

\documentclass{article}
%\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{unicode-math}
\begin{document}
{\Huge $\mathbb{R}$}
\end{document}

So the answer would be: either a truetype/opentype version of amsfonts, or unicode-math can still use legacy fonts, if desired.

unicode-math access is by $\symbb{R}$.

=============

Original post:

I've seen that one before.

A sort of sans libertine/helvetica flavour.

Some random samples, none with a straight leg:

\documentclass[12pt]{article}
\usepackage{fontspec}
\usepackage{xcolor}
\pagecolor{red!3}


\newcommand\SampleText{\symbol{"211D}}


\newfontface\fra{Arial Unicode MS}
\newfontface\frb{Cambria Math}
\newfontface\frc{DejaVu Math}
\newfontface\frd{DejaVu Math TeX Gyre}
\newfontface\fre{DejaVu Sans}
\newfontface\frf{DejaVu Sans Mono}
\newfontface\frg{DejaVu Serif}
\newfontface\frh{Fira Math}
\newfontface\fri{FreeSans}
\newfontface\frj{FreeSerif}
\newfontface\frk{FreeSerifAvvaShenouda}
\newfontface\frl{GFS Neohellenic Math}
\newfontface\frm{Honoka Antique-Kaku}
\newfontface\frn{Honoka Antique-Maru}
\newfontface\fro{HPMLinux Biolinum O}
\newfontface\frp{HPMLinux Libertine O}
\newfontface\frq{Kabala}
\newfontface\frr{Libertinus Math}
\newfontface\frs{Libertinus Mono}
\newfontface\frt{Libertinus Sans}
\newfontface\fru{Libertinus Serif}
\newfontface\frv{Libertinus Serif Display}
\newfontface\frw{Linux Biolinum}
\newfontface\frx{Linux Biolinum G}
\newfontface\fry{Linux Biolinum O}
\newfontface\frz{Lucida Sans Unicode}

\newcommand\printther[2]{{#1\huge    \SampleText} -- #2}


\begin{document}


\printther{\fra}{Arial Unicode MS}

\printther{\frb}{Cambria Math}

\printther{\frc}{DejaVu Math}

\printther{\frd}{DejaVu Math TeX Gyre}

\printther{\fre}{DejaVu Sans}

\printther{\frf}{DejaVu Sans Mono}

\printther{\frg}{DejaVu Serif}

\printther{\frh}{Fira Math}

\printther{\fri}{FreeSans}

\printther{\frj}{FreeSerif}

\printther{\frk}{FreeSerifAvvaShenouda}

\printther{\frl}{GFS Neohellenic Math}

\printther{\frm}{Honoka Antique-Kaku}

\printther{\frn}{Honoka Antique-Maru}

\printther{\fro}{HPMLinux Biolinum O}

\printther{\frp}{HPMLinux Libertine O}

\printther{\frq}{Kabala}

\printther{\frr}{Libertinus Math}

\printther{\frs}{Libertinus Mono}

%\printther{\frt}{Libertinus Sans}
%
%\printther{\fru}{Libertinus Serif}
%
%\printther{\frv}{Libertinus Serif Display}
%
%\printther{\frw}{Linux Biolinum}
%
%\printther{\frx}{Linux Biolinum G}
%
%\printther{\fry}{Linux Biolinum O}

\printther{\frz}{Lucida Sans Unicode}

{\fra \SampleText}
{\frb \SampleText}
{\frc \SampleText}
{\frd \SampleText}
{\fre \SampleText}
{\frf \SampleText}
{\frg \SampleText}
{\frh \SampleText}
{\fri \SampleText}
{\frj \SampleText}
{\frk \SampleText}
{\frl \SampleText}
{\frm \SampleText}
{\frn \SampleText}
{\fro \SampleText}
{\frp \SampleText}
{\frq \SampleText}
{\frr \SampleText}
{\frs \SampleText}
{\frt \SampleText}
{\fru \SampleText}
{\frv \SampleText}
{\frw \SampleText}
{\frx \SampleText}
{\fry \SampleText}
{\frz \SampleText}


\end{document}

====

For completeness, a fuller gallery, in parts, more systematically arranged.

(1) These are (some of) the ones with "Math" in the font name:

And then in order of decreasing coverage of the Letterlike Symbols unicode block:

(2)

(3)

(4)

(5)

(6)

And arbitrarily stop there, with a coverage of 20 out of 80 glyphs in the block.

There is obviously something very interesting going on with fonts.

Cambria Math uses a nearly-identical glyph. Ironically, you’d need to pay money for this copyrighted font, even though the reason you want it is that they ripped off someone else’s design. (It’s owned by Microsoft and included with Windows and Office. If you dual-boot Linux, you could make a symbolic link from the font file on your Windows partition to ~/.fonts or /usr/local/share/fonts. You could also buy the font from Monotype.)

You can select math alphabets or individual glyphs from the font of your choice with the range= option of \setmathfont. For example:

\documentclass{article}
\usepackage{unicode-math}

\setmathfont{Latin Modern Math}
\setmathfont{TeX Gyre Pagella Math}[range={bb,bbit}, Scale=MatchUppercase]

\begin{document}
\[ \mathbb{CDHNRQSZ} \]
\end{document}

Or with the font changed to:

\setmathfont{TeX Gyre DejaVu Math}[range={bb,bbit}, Scale=MatchUppercase]

You can change only the ℝ with

\setmathfont[range=`ℝ]

or

\setmathfont[range=\BbbR]