Size does matter, as the woman say. :wink:
The un-cast pine cones you see people make have a large core. The size of the outside of the pine cone is not relevant. It's the core that will matter. If you take a typical Ohio/Michigan pine cone and try and drill through the center..first off..good luck finding the center, second off, the core is going to be smaller in diameter than the pen. I'd be surprised if you found one as big as a slim tube. So if you drill it down the center, the core is going to be completely gone, and then what is holding all the leaves in place???
There are people around that sell the large core cones, think they grow out there in California, Oregon and probably lots of other places like that. This does not mean the Ohio cones are not good, or you can't make pens out of them, you just can't do it that way. you need to dry your cones, then trim them square to fit in a mold and then cast them with Alumilite. Probably easier and cheaper if you want your style of cone, to just purchase them already cast.