Don't ever fold or bend them too tightly. The pre-1960s ones can be loosely rolled (as the felt is typically a lot softer). Many people are worried about the felt wrinkling or creasing, but the bigger concern is the painted graphics. If bent too severely, the graphics tend to pucker and/or crack.
I prefer packing them all flat, but that's obviously a more costly way to go. If a seller is hell-bent on rolling it up, I'll sometimes offer to pay extra shipping for the flat package. Hope this helps
