How to make scalable curly braces wider or thicker

[loudcat]

I have been using scalable curly braces on the sides of a matrix that I use to create piecewise functions and other math formulas using LibreOffice Math. My main issue is that the curly braces are too thin.

For example, here is a Math formula that produces a piecewise function:

f(x) =
left lbrace matrix {
	alignl { 2(x+1) } # "for" x <= -2     ##
	alignl {-1}       # "for" -2 < x <= 3 ##
	alignl {alignc {1 over 2} (x - 1)} # "for" x > 3
} right rbrace

And here is the resulting image:

I would prefer if the curly braces on the left and right side of the ‘matrix’ were wider. As they are, they don’t really look like curly braces, as I can barely see the ‘curl,’ and the tip isn’t obvious.

This isn’t unique to matrices, by the way. It’s just how scalable curly braces look (possibly just on my system). Here’s an example of scalable curly braces and “plaintext” curly braces:

left lbrace { y = mx + b } right rbrace

newline

"{" y = mx + b "}"

(I would post a screenshot of this formula but as a new user I can only include 1 upload)

I quite like the way “plaintext” braces (or whatever you call quote-escaped symbols) look. Is there a way to make the scalable curly braces look similar?

Here is my system information:
Version: 7.3.7.2 / LibreOffice Community
Build ID: 30(Build:2)
CPU threads: 4; OS: Linux 6.5; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Ubuntu package version: 1:7.3.7-0ubuntu0.22.04.4
Calc: threaded

I am running Ubuntu 22.04.3 LTS on Wayland using GNOME version 42.9 on a 64-bit OS

Thank you for your time!

[EarnestAl]

Making it bold doesn’t emphasise the curve. Maybe change the font, the Microsoft supplied Cambria Math has heavier, more pronounced braces.

I see there is a Noto Sans Math available in Google Fonts, Noto Sans Math - Google Fonts, maybe that has braces more to your liking.
[Edit]
For LibreOffice 24.0.2
Noto Sans Math doesn’t extend far enough top and bottom:

Libertinus Math doesn’t extend far enough at the top so there is not enough space after the =

That two fonts show unexpected behaviour in LibreOffice is a concern

[loudcat]

I’ll try that out, thank you. After reviewing the font settings (through Format > Fonts...) I only see options to change the font for variables, functions, numbers, text, serif, sans-serif, and fixed-width. None of these sound like they apply only to curly braces and other symbols. Which one should I change?

[EarnestAl]

For the screenshot, I changed just Math I think. Anyway, Math will be the one with the maths symbols in it
There aren’t many math fonts around

[loudcat]

Sorry, I don’t see a Math option. Am I looking at the wrong menu?

[EarnestAl]

Sorry, that was with LibreOffice 24.0.2 which seems to have an extra font setting above variable.

[Lupp]

See also tdf#32362

[ajlittoz]

fter experimenting, I came up with

f(x) =
bold left lbrace nbold
matrix {
	alignl { 2(x+1) } # "for" x <= -2     ##
	alignl {-1}       # "for" -2 < x <= 3 ##
	alignl {alignc {1 over 2} (x - 1)} # "for" x > 3
} right rbrace

Note bold/nbold only enclose the left scalable bracket and it also applies to the right scalable bracket.

However, the result is ugly because the curly bracket is likely drawn as two separate shapes. These half-shapes are embolden by the trick but their positions are not adjusted and we see that the global shape has now bleeding artefacts at their ends.

There is presently no acceptable solution.