Thanks guys for the advice, I also read 1 cubic inch per pound on many urn sites. I've got some good ideas and just have to see how I'm putting this together with what I have cut. This will be a pretty big box as I will have space in the top for photos or mementos as well. Those photos you guys posted are gorgeous and I hope mine turns out as nice.
John, not opposed to the plastic at all, just wondering what the norm was.
Thanks again guys.