Hi,
I mark almost all my chicken hatching eggs with a Sharpie permanent marker.
The marker doesn't penetrate the shell or the membrane at all.
The eggs hatch well, too
I'd be comfortable using a Sharpie on duck eggs as well.
Good luck,
Lisa
I mark almost all my chicken hatching eggs with a Sharpie permanent marker.
The marker doesn't penetrate the shell or the membrane at all.
The eggs hatch well, too
![smile.png](https://www.backyardchickens.com/img/smilies/smile.png)
I'd be comfortable using a Sharpie on duck eggs as well.
Good luck,
Lisa