Bold text in SVG is too thick and looks fuzzy (like it's stroked additionally).
eg, this svg <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 760 800" preserveAspectRatio="xMinYMin meet"><text class="title" x="380" y="20" text-anchor="middle" font-weight="bold" style="font-size: 16px;">Bold text sample</text></svg>
generated with pdfmake:

and pdfkit:

and it the playground:

I also noticed that it was good in version 0.1.61, but then something's happened.
generated with 0.1.61:

and current:

Fixed by commit https://github.com/bpampuch/pdfmake/commit/31a505f26beea5ee6606debbca78816ce4216226 (in 0.1 branch) and https://github.com/bpampuch/pdfmake/commit/1bb014f0e8ed9902520e227f2f7f13aa06017878 (in master).
Most helpful comment
Fixed by commit https://github.com/bpampuch/pdfmake/commit/31a505f26beea5ee6606debbca78816ce4216226 (in 0.1 branch) and https://github.com/bpampuch/pdfmake/commit/1bb014f0e8ed9902520e227f2f7f13aa06017878 (in master).