I once found a rather gigantic dead spider in the attic....Also used it for Stacking practice.

There is a new Stacking Program , that just had its first release. OpenSource, Crossplatform

"FocusForge" By "jjjsood" on github, the Author seeks beta testers. I put it to use already, good results;

Is in active developement. Feed it TiFFs, and it will Stack nicely!