# A replacement to "\mathbbm{1}" with type-1 fonts

I use the symbol "\mathbbm{1}" to produce a nice-looking "1" digit. But, then my PDF contains a "Type-3" font, which is not allowed by my publisher. Is there a replacement that does not use a type-3 font?

• The STIX fonts contain blackboard bold digits, although the style is different from that of the font you are now using. Mar 12, 2019 at 19:34
• Does your publisher accept documents made with OpenType math fonts? Apr 11, 2019 at 22:16
• @Davislor good question. I had to submit a month ago, so I just put a usual "1" instead of the fancy 1, and submitted. I do not know whether OpenType fonts are accepted. Apr 12, 2019 at 5:31
• The question specifies Type-1, but this is one of many, many problems that can be solved going forward by switching to unicode-math, since all up-to-date OpenType math fonts support \mathbb{1}. If, that is, a publisher allows it. Apr 12, 2019 at 7:40
• @Davislor thanks, I will check this out the next time I run into a similar problem. Apr 12, 2019 at 13:06

The doublestroke package provides blackboard fonts in type 1 format, including the \mathds{1} that you are looking for.

It does not exactly look like those of bbm, but could likely be used as a drop in replacement in your case

Another possibilty is use the package bbold symbol font to get a similar \mathds{1}.

\documentclass{article}
\usepackage{bbold}
\usepackage{mathtools}

\begin{document}
$\mathbb{1}$

\end{document}


Using dsfont you will have:

\documentclass{article}
\usepackage{dsfont}
\begin{document}
$\mathds{1}$
\end{document}

• Note that the use of the package bbold will also change other mathbb characters you might have used (set N of natural numbers, R, C, etc.) Sep 12, 2019 at 21:11
• @Karlo I agree with you; it always depends on what you want to create. In my case I have a lot of packages loaded for a personal project and I didn't have any problems. Sep 12, 2019 at 21:15