Fonts and subtractive silkscreen

[Pack34]

I've noticed in some designs have a much smoother font as well as subtractive silkscreen text. Take for example, the silk in the newer Arduino Due and the Mojo Spartan 6.

I've seen examples using subtractive text in a copper layer but not silk. Is this all done through importing bitmaps, or is there a more elegant solution using built in tools?

http://arduino.cc/en/uploads/Main/ArduinoDue_Front.jpg
https://embeddedmicro.com/products/mojo-v2.html

[ludzinc]

I don't know about other CAD packages, but Altium will let you use your systems True Type Fonts, and have a 'negative' option (rectangle with voided text).

[MarkL]

There's a ULP on CadSoft's web page:

  negasilk.ulp: This ULP generates for inverse text on the silkscreen.

Download: http://www.cadsoftusa.com/downloads/file/negasilk.zip

Subtractive text in copper can be done by drawing a polygon in the Top or Bottom layer and then overlaying it with text in the tRestrict or bRestrict layer.

EDIT: Fixed link (thanks for the URL mangling, forum SW...)