blackboard-bold/double-struck capital greek letters

Question

I am trying to show blackboard bold capital greek letters in a document. Font is standard serif font. Math is straight not italic. I made countless attempts based on SE solutions, to no avail. Here is a MWE:

\documentclass{article}
\usepackage{amsfonts} % for mathbb command
\usepackage[symbolgreek]{mathastext} % if you remove this it is even worst
\begin{document}
$a b c \gamma \delta \pi A B C \Gamma \Delta \Pi \mathbb{A B C \Gamma \Delta \Pi}$
\end{document}

Can someone help?

Do you mean these, ℼℽℾℿ⅀, or any Greek? What would bold signify? — Cicada, Jun 25 '22 at 14:58
Can you use XeLaTeX/LuaLaTeX? \usepackage[math-style=upright]{unicode-math} works for everything for me except the bb \Delta. Not sure why that's missing; doesn't seem to be in unicode. — frabjous, Jun 25 '22 at 15:10
My misubderstanding: 'bb' means 'blackboard bold', not 'blackboard'. @frabjous: no bb Delta or delta: "5.4.2 Double-struck The double-struck style (also known as ‘blackboard bold’) consists of upright Latin letters {–,ℤ}, numerals –, summation symbol ⅀, and four Greek letters only: {ℽℼℾℿ}." — Cicada, Jun 26 '22 at 06:27
Not a duplicate but similar in what is wanted; this may be helpful: https://tex.stackexchange.com/q/661388 — barbara beeton, Nov 24 '22 at 01:53

score 4 · Answer 1 · answered Dec 24 '22 at 10:06

Unicode, and therefore unicode-math supports three blackboard-bold Greek letters, ℽ (\Bbbgamma), ℾ (\BbbGamma) and ℿ (\BbbPi).

However, with unicode-math, if you can find a suitable Greek double-struck OpenType or TrueType font, you can declare it as a math alphabet.with, e.g.

\usepackage{unicode-math}
\setmathfontface\mathbbgreek{Some Outline Greek Font}[Scale=MatchUppercase]

This lets you write

$\mathbbgreek{\mupTheta}$

One package that supports this for legacy TeX is:

\documentclass{article}
\usepackage[bbgreekl]{mathbbol}
\begin{document}
( \mathbb{\Theta\Phi\Gamma} )
\end{document}

score 3 · Answer 2 · answered Jun 26 '22 at 07:09

A sort of bb for Greek could be emulated:

(My screen image is rasterizing; the PDF is OK.)

MWE

\documentclass{article}
\usepackage{xcolor}
\usepackage{amsmath}
\usepackage{amsfonts}
\newcommand{\bbg}[1]{%
\ooalign{$#1$\cr\raisebox{-.2pt}{$#1$}\cr\raisebox{.2pt}{$#1$}\cr\textcolor{white}{$\mkern0.2mu#1$}}%
}
\begin{document}
$\mathbb{D}$\ooalign{$\mathbb{D}$\cr$\mkern0.5mu\mathbb{D}$}
$\Delta$\ooalign{$\Delta$\cr\raisebox{-.2pt}{$\Delta$}\cr\raisebox{.2pt}{$\Delta$}\cr\textcolor{white}{$\mkern0.2mu\Delta$}}
\bbg{\delta}
\bbg{\Phi}\bbg{\kappa}\bbg{\Xi}
\end{document}

score 3 · Answer 3 · answered Dec 24 '22 at 14:29

Altering Petr Olsak's faked bold trick slightly may suit your needs:

\def\doublestroke#1{\pdfliteral{1 Tr .3 w}#1\pdfliteral{0 Tr 0 w}}
[ \doubestroke{\Phi \Gamma \Delta} ]

What this does is simply strokes the letters without filling them (a list of possible values for Tr can be found in section 5.2.5 of Adobe's PDF reference, page 402). You may wish to alter the value .3 to your liking (increase for a heavier stroke).

It's worth noting that this macro will also work with identical results outside of math mode.

score 2 · Answer 4 · answered Nov 23 '22 at 14:28

Is this suits for you?

\documentclass{article}
\usepackage{amsfonts} % for mathbb command
\usepackage[symbolgreek]{mathastext} % if you remove this it is even worst
\usepackage[copies]{contour}%
\contourlength{1pt}%
\begin{document}
\newcommand*{\outline}[1]{\color{white}\contour{black}{#1}}%
$\outline{$a b c \gamma \delta \pi A B C \Gamma \Delta \Pi$} 
\mathbb{A B C} \outline{$\Gamma \Delta \Pi$}$
\end{document}

Output

blackboard-bold/double-struck capital greek letters

4 Answers4