Good idea. I wrote on some regular paper and then soaked it for about 10 minutes. I had to rub pretty hard to get it to begin to run, so I think it will be ok. I have Rite-in-the Rain paper in my kit so maybe I will try it with that just to be sure. The pen core sure saves a lot of space over the pencil.

Thanks to everyone for the suggestions.

Regards, Vince