# How to create this gamma symbol

How do I create this gamma symbol?

A Gamma is an upside down L:

\documentclass{article}
\usepackage{amssymb,graphicx}

\newcommand{\bbGamma}{{\mathpalette\makebbGamma\relax}}
\newcommand{\makebbGamma}[2]{%
\raisebox{\depth}{\scalebox{1}[-1]{$\mathsurround=0pt#1\mathbb{L}$}}%
}

\begin{document}

$\Gamma\bbGamma \mathrm{L}\mathbb{L}$

\end{document}


• I would never guessed that... – manooooh Sep 23 '18 at 16:36
• That "trick" would ruin the document for copy/pasting, screen readers, search engines, etc. – YSC Sep 24 '18 at 11:04
• @YSC Because copy pasting math works so flawlessly all the other times? – Henri Menke Sep 24 '18 at 11:25
• @HenriMenke Are you saying that since some documents containing a Gamma are already un-copiable, we should make all such documents ruined for copy/pasting, screen readers and search engines? egreg's answer displays a really nice trick; anyone which uses it should be aware of its consequences, though. – YSC Sep 24 '18 at 12:05

You could use the package https://ctan.org/pkg/unicode-math and choose a math font. That way you get a concise set of glyphs (as long as the typeface's designer did their job well). You should also consider https://ctan.org/pkg/fontspec for a coherent use of typefaces in math mode and text mode. The following examples generate serif blackboard bold capital gammas.

The following glyphs should all be the same (and they look alike to me).

\documentclass{memoir}
\usepackage{amsmath}

\usepackage{unicode-math}
\setmathfont{Asana Math}

\begin{document}
$\BbbGamma \mathbb{\Gamma} \mathbb{Γ} \symbb{\Gamma} \symbb{Γ} ℾ \symbol{"213E}$
\end{document}


EDIT: You can also apply egreg's solution to another underrated font which blends well with CM and LM, please compare them yourself:

\documentclass[landscape]{memoir}
\usepackage{amsmath}
\usepackage{graphicx,dsfont,amssymb,booktabs}

\newcommand\BbbGamma{\reflectbox{\rotatebox[origin=c]{180}{$\mathds L$}}}
\newcommand\BbbGammaVar{\reflectbox{\rotatebox[origin=c]{180}{$\mathbb L$}}}

\begin{document}
\begin{tabular}{*{16}{>{$}c<{$}} }
\toprule
\BbbGamma & \mathds h & \mathds k & \mathds 1 & \mathds A & \mathds B & \mathds C & \mathds D & \mathds E & \mathds F & \mathds G & \mathds H & \mathds I & \mathds J & \mathds K \\
\Gamma & \text h & \text k & \text 1 & \text A & \text B & \text C & \text D & \text E & \text F & \text G & \text H & \text I & \text J & \text K \\
\BbbGammaVar & \mathbb h & \mathbb k & \mathbb 1 & \mathbb A & \mathbb B & \mathbb C & \mathbb D & \mathbb E & \mathbb F & \mathbb G & \mathbb H & \mathbb I & \mathbb J & \mathbb K \\
\midrule
\mathds L & \mathds M & \mathds N & \mathds O & \mathds P & \mathds Q & \mathds R & \mathds S & \mathds T & \mathds U & \mathds V & \mathds W & \mathds X & \mathds Y & \mathds Z \\
\text L & \text M & \text N & \text O & \text P & \text Q & \text R & \text S & \text T & \text U & \text V & \text W & \text X & \text Y & \text Z \\
\mathbb L & \mathbb M & \mathbb N & \mathbb O & \mathbb P & \mathbb Q & \mathbb R & \mathbb S & \mathbb T & \mathbb U & \mathbb V & \mathbb W & \mathbb X & \mathbb Y & \mathbb Z \\
\bottomrule
\end{tabular}
\end{document}


Top row: \mathds, middle row: Latin Modern, bottom row: \mathbb. My understanding is that \mathds is actually much closer to what someone would expect from a blackboard bold by just add a single double stroke on a blackboard than \mathbb.

The website https://www.fileformat.info/info/unicode/char/213e/fontsupport.htm# gives a comparison of various typefaces.

• +1. With unicode-math, you can also write \BbbGamma or \symbb{\Gamma}. You can additionally use \setmathfont[range={bb, bbit}, Scale=MatchUppercase]{...} to use your double-struck alphabet of choice, including any TrueType or OpenType font. – Davislor Sep 23 '18 at 17:25
• @Davislor Indeed, RTFM (read the fine manual) is beneficiary. The new options the engines LuaTeX and XeTeX offer are astounding. – CampanIgnis Sep 23 '18 at 17:29
• All of those commands produce the same output: ℾ (U+213E), but there is one difference. If you \setmathfont[range=bb], the \symbb command will correctly use the symbol from the selected blackboard font. I haven’t extensively tested, but I’ve noticed that \mathrm, etc. often keep using the main font. – Davislor Jun 26 '19 at 15:03
• Oh, and at least two other ways: \char"213e and ^^^^213e. – Davislor Jun 26 '19 at 15:05

WARNING: Some long time ago there was some package for this, I do not remember the details. I guess it was somehow related to this thingy. And I cannot really tell you why this was dropped, perhaps this discussion helps you.

Anyway, I kept excerpts of this on my machine and usually do something like this

\documentclass{article}
\newcommand{\bbfamily}{\fontencoding{U}\fontfamily{bbold}\selectfont}
\DeclareMathAlphabet{\mathbb}{U}{bbold}{m}{n}
\DeclareSymbolFont{bbold}{U}{bbold}{m}{n}
\SetSymbolFont{bbold}{bold}{U}{bbold}{m}{n}
\DeclareMathSymbol{\bbGamma}{\mathord}{bbold}{'000}
\DeclareMathSymbol{\bbDelta}{\mathord}{bbold}{'001}
\DeclareMathSymbol{\bbVarTheta}{\mathord}{bbold}{'002}
\DeclareMathSymbol{\bbLambda}{\mathord}{bbold}{'003}
\DeclareMathSymbol{\bbTheta}{\mathord}{bbold}{'004}
\DeclareMathSymbol{\bbPi}{\mathord}{bbold}{'005}
\DeclareMathSymbol{\bbSigma}{\mathord}{bbold}{'006}
\DeclareMathSymbol{\bbUpsilon}{\mathord}{bbold}{'007}
\DeclareMathSymbol{\bbPhi}{\mathord}{bbold}{'010}
\DeclareMathSymbol{\bbPsi}{\mathord}{bbold}{'011}
\DeclareMathSymbol{\bbOmega}{\mathord}{bbold}{'012}
\DeclareMathSymbol{\bbalpha}{\mathord}{bbold}{"0B}
\DeclareMathSymbol{\bbbeta}{\mathord}{bbold}{"0C}
\DeclareMathSymbol{\bbgamma}{\mathord}{bbold}{"0D}
\DeclareMathSymbol{\bbdelta}{\mathord}{bbold}{"0E}
\DeclareMathSymbol{\bbespilon}{\mathord}{bbold}{"0F}
\DeclareMathSymbol{\bbzeta}{\mathord}{bbold}{"10}
\DeclareMathSymbol{\bbeta}{\mathord}{bbold}{"11}
\DeclareMathSymbol{\bbtheta}{\mathord}{bbold}{"12}
\DeclareMathSymbol{\bbiota}{\mathord}{bbold}{"13}
\DeclareMathSymbol{\bbkappa}{\mathord}{bbold}{"14}
\DeclareMathSymbol{\bblambda}{\mathord}{bbold}{"15}
\DeclareMathSymbol{\bbmu}{\mathord}{bbold}{"16}
\DeclareMathSymbol{\bbnu}{\mathord}{bbold}{"17}
\DeclareMathSymbol{\bbxi}{\mathord}{bbold}{"18}
\DeclareMathSymbol{\bbpi}{\mathord}{bbold}{"19}
\DeclareMathSymbol{\bbrho}{\mathord}{bbold}{"1A}
\DeclareMathSymbol{\bbsigma}{\mathord}{bbold}{"1B}
\DeclareMathSymbol{\bbtau}{\mathord}{bbold}{"1C}
\DeclareMathSymbol{\bbupsilon}{\mathord}{bbold}{"1D}
\DeclareMathSymbol{\bbphi}{\mathord}{bbold}{"1E}
\DeclareMathSymbol{\bbchi}{\mathord}{bbold}{"1F}
\DeclareMathSymbol{\bbpsi}{\mathord}{bbold}{"20}
\DeclareMathSymbol{\bbomega}{\mathord}{bbold}{"7F}
\DeclareMathSymbol{\bbell}{\mathord}{bbold}{"40}
\newcommand{\BBsymbol}[1]{%
\ifcat#1a\mathbbm{#1}\else
\ifx#1\Gamma\bbGamma\fi
\ifx#1\Delta\bbDelta\fi
\ifx#1\VarTheta\bbVarTheta\fi
\ifx#1\Lambda\bbLambda\fi
\ifx#1\Theta\bbTheta\fi
\ifx#1\Pi\bbPi\fi
\ifx#1\Sigma\bbSigma\fi
\ifx#1\Upsilon\bbUpsilon\fi
\ifx#1\Phi\bbPhi\fi
\ifx#1\Psi\bbPsi\fi
\ifx#1\Omega\bbOmega\fi
\ifx#1\alpha\bbalpha\fi
\ifx#1\beta\bbbeta\fi
\ifx#1\gamma\bbgamma\fi
\ifx#1\delta\bbdelta\fi
\ifx#1\espilon\bbespilon\fi
\ifx#1\zeta\bbzeta\fi
\ifx#1\eta\bbeta\fi
\ifx#1\theta\bbtheta\fi
\ifx#1\iota\bbiota\fi
\ifx#1\kappa\bbkappa\fi
\ifx#1\lambda\bblambda\fi
\ifx#1\mu\bbmu\fi
\ifx#1\nu\bbnu\fi
\ifx#1\xi\bbxi\fi
\ifx#1\pi\bbpi\fi
\ifx#1\rho\bbrho\fi
\ifx#1\sigma\bbsigma\fi
\ifx#1\tau\bbtau\fi
\ifx#1\upsilon\bbupsilon\fi
\ifx#1\phi\bbphi\fi
\ifx#1\chi\bbchi\fi
\ifx#1\psi\bbpsi\fi
\ifx#1\omega\bbomega\fi
\ifx#1\ell\bbell\fi
\fi
}

\begin{document}
$\BBsymbol{\Gamma}\BBsymbol{\alpha}$
\end{document}


And of course the outcome is not as nice as in egreg's answer but here you have double stroke letters for all Greek letters. (And those who feel like they need to shout at me: this post starts with a big disclaimer... ;-)

• Just to add: I really do not know why there is no standard package for this, which also provides a non-pixelated versions of the \mathbbm{C} letters which come with the bbm package. By "I really do not know" whether these are legal or technical issues, or nobody feels if this something good to have. At least I would think this would be something good to have, and would be happy to spend some time to make this work. However, I have no idea how to design a font, and perhaps more importantly I do not know anything about the legal issues. – user121799 Sep 23 '18 at 16:45
• If you want to keep compatibility with other packages, unicode-math uses the macros \BbbGamma, etc. – Davislor Sep 23 '18 at 17:28
• @Davislor I stressed that I do not know why the package has been changed. (However, I would also not really recommend using unicode-math, but I kindly like to ask you not to start a discussion on this because there are simply different opinions and I am not sure we will find an agreement.) Anyway, thanks for the comment! I am sure that there are pitfalls and reasons why the old package has disappeared (yet I am using the above without problems in many documents). – user121799 Sep 23 '18 at 17:31
• I agree that this isn't the time or place for that discussion. I simply was noting that, if you use the same command names as other packages, it eases copy-paste and migration. – Davislor Sep 23 '18 at 17:52
• @marmot I would like to hear why you do not recommend unicode-math (generally?). I would like to learn from a experienced TeXnician of good reputation like you. I do not want to misuse this command section for a discussion, so is there a blog (or something similar) you might refer to? – CampanIgnis Sep 24 '18 at 8:53

I recommend unicode-math for new documents, as CampanIgnis already posted. There are several different packages that support double-struck blackboard-bold Greek letters for legacy NFSS, including:

\documentclass[varwidth, preview]{standalone}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[bbgreekl]{mathbbol}

\begin{document}
$$\mathbb{\Gamma}$$
\end{document}


Other packages including these symbols are stix and mbboard.

• I have used your code for a colleague :-). – Sebastiano Jun 26 '19 at 14:50

this works as well:

\documentclass{standalone}

\newcommand\mygamma{$\mathrm{I} \hspace{-0.4ex} \Gamma$}

\begin{document}

\tiny \mygamma
\small \mygamma
\normalsize \mygamma
\large \mygamma
\Large \mygamma
\Huge \mygamma

\end{document}


produces this result:

it works also with other letters, e.g. R or N (real or natural numbers):

\newcommand\myr{$\mathrm{I} \hspace{-0.4ex} \mathrm{R}$}
\newcommand\myn{$\mathrm{I} \hspace{-0.4ex} \mathrm{N}$}


I also like the contour package

\documentclass[a4paper,12pt]{article}
\usepackage[outline]{contour}
\newcommand*{\fancy}[1]{\color{white}\contour{black}{#1}}
\begin{document}
\fancy{$\Gamma$}
\end{document}