Original drawing of Menger Sponge made in SketchUp. Exported raster graphic to Adobe Photoshop CS6 printed to bond paper and traced with fine tip fountain pen and with Pentel "Sign" fiber tip pen. Photographed and converted to raster graphic in Photoshop.
<a href="//commons.wikimedia.org/wiki/User:Eric_Inglert" title="User:Eric Inglert">Eric Inglert</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>