Replace integral sign in CM(U) Bright with Iwona while keeping proper position of integral limits

Question

I am typesetting my thesis in CMU Bright OpenType using font spec. For the math fonts I'm using the CM Bright T1 font.

The result looks nice except for the integral sign which does not match of other glyphs. Therefore I'm trying to display that sign using the Iwona font (which mathes nicely).

Everything works except for the position of the lower and upper limit on the integral. When using Iwona these are display closer to the middle of the line than they should be.

Minimal working example:

\documentclass[a4paper]{article}

%MATH FONTS: CM Bright (T1)
\usepackage[T1]{fontenc}
\usepackage{cmbright} %for math only

\usepackage{fontspec}
%MAIN FONT: Computer Modern Unicode (CMU) Bright (open type)
\setmainfont[BoldFont={cmunbbx.otf},ItalicFont={cmunbmo.otf},BoldItalicFont={cmunbxo.otf}]{cmunbmr.otf}

\newfontfamily\integralfont{Iwona}
\newcommand{\myint}{$\integralfont ∫$}

\begin{document}
This is some text (CMU Bright OpenType)

Some math (CM Bright T1, except 2nd integral: Iwona T1): $\int_{0}^{10} f(x) = \myint_{0}^{10}  g(x)$
\end{document}

The gives the following result:

Notice the difference in the position of the integral limits (0 and 10). They are further apart when they follow the first integral sign (set with CM Bright) than when they follow the second integral sign (set with Iwona).

Can anyone help me fix this? I have experimented with \displaylimits but couldn't get it to work right (or it didn't make a difference).

Answer 1

Put the following code in your preamble:

\DeclareSymbolFont{iwonalargesymbols}{OMX}{iwona}{m}{n}
\DeclareMathSymbol{\intop}{\mathop}{iwonalargesymbols}{"52}

If you want to change all large symbols to Iwona (cmbright uses the default Computer Modern Extensions font), then

\DeclareSymbolFont{largesymbols}{OMX}{iwona}{m}{n}

will suffice.

Then you'll use the usual \int command.