I am no expert but it would seem to me the finer the mix the better the detail would be in doing imprints of leaves.I have done a couple and being they are not toted around I was not so concerned with weight so I went with a fine sand and portland sand mix. Surely not the lightest of things but the results and detail were very good.

Spears? I am picturing Neptune's spear, but somehow I do not think that is what you mean.

middle Tn, Are you talking about leaf castings or making imprints in stepping stones or planters? Why can't you get white portland, no masonary supply places near you?
bonecarver, I think it's "spheres", ya know balls. Billie

Yes Im talking about spheres", forgive my spelling I was posting late. as for the imprints I have been trying to make pots but would like to have leaf imprints on them and they are just not coming out well at all. I know I need a finer mix using sand yet I dont want them to heavy.
Now back to the spheres . To give you a visual Im trying to make a Bird feeder beachball sized it will hang from the tree. It will have 2-3 oval holes cut in it for access to the food and it will have a little roof overhang to protect from the rain . I have made several very small one and they are really cute but I want a bigger one the problem is they just get way to heavy. I didnt take pictures of the ones I made and gave them away for a fund raiser so I dont have a picture . So Im guess I looking for two recipe here one that is fine and lighweight and one that is just super lightweight . Am I asking to much here . I knwo where there is a vision there has got to be a way .....Thanks for your questions I appreciate it . As for the white portland I have searched all over and can not find it . If you know somewhere between Nashville, tn and Huntsville, al that carries White please let me know .
Thanks

No need to apologize for spelling, it was an elective at my school... I need to read and not browse the articles. I have a [not sure I can legally call it]sphere started from one of those exercise balls it seems get purchased for just this reason. I am still um experimenting with different mixes on it so I will just for your sake stay out of this an let Billie or some of the others answer..

mid TN, Call any masonry supply or decorative concrete supplier and asked them for a bag of white portland cement. They all carry it. You just won't find it at the big home improvement stores or your local hardware store. Though both places can order it for you
Regarding leaf imprints, did you search on this forum or on the gallery side of this forum? I listed one but I'm sure there are others on this side of the forum and on the gallery side.
Hanging the cement mix bird feeders, no matter what the weight, is a problem. You are better off mounting them from a post. I only know of one super light weight mix that would work for hanging and it's proprietary. Billie

Here is a link that might be useful: leaf imprints