I'm trying to figure out how I could set which issue shows up for the thumbnail under Series stacking. For instance, one of the Specials for Preacher shows up as the series thumbnail instead of the preferred issue number one. Is it possible to set your own thumbnail? If not, by which criteria does it choose the thumbnail that it uses for a series?

Thanks in advance.

Double-click on the stack to view all the issues. Right click on the issue to use and select "Set as Top of Stack".

Oh, man. I don't know how I didn't see that. Thanks!