1. Find org-netbeans-modules-editor-settings-CustomPreferences.xml in ~/.netbeans/x.x/config/Editors/Preferences where x.x is your netbeans version.
In my case, this was C:\Users\Andrei\AppData\Roaming\NetBeans\8.0\config\Editors\Preferences\org-netbeans-modules-editor-settings-CustomPreferences.xml
NOTE.: By trial and error I found that this file is generated only after you first run NetBeans first time. I’ve just installed it on my home computer and decided to do all the changes first, and this file was nowhere to be found on my pc, so I had to run first netbeans and then edit the xml config file.
2. Add this xml markup just above </editor-preferences> or anywhere if you know what you doing.
<entry javaType="java.lang.Float" name="line-height-correction" xml:space="preserve">
<value><![CDATA[1.4]]></value>
</entry>