bll 2016-05-10: The standard ttk::checkbutton does not scale well for 4K displays. This code is a pure tcl implementation of checkbuttons with no graphics. It includes styling for all 22 themes. I have attempted to match each theme's styling reasonably well. The package will change themes on a <<ThemeChanged>> event.
Place the package require in your code after tk scaling has been set.
Download from:
http://gentoo.com/tcl/checkButtonScaled.tcl%|%http://gentoo.com/tcl/checkButtonScaled.tcl%|%
Version 1.7 2016-5-11
Version 1.6 2016-5-10
dbohdan 2016-05-12: The fact that you have a styling for each of the 22 themes is impressive.
Could you put a high-DPI screenshot of the widget on this page?